PHYSICAL SCIENCES
EXAMINATION GUIDELINES
GRADE 12
2021

Related Items

1. INTRODUCTION
   The Curriculum and Assessment Policy Statement (CAPS) for Physical Sciences outlines the nature and purpose of the subject Physical Sciences. This guides the philosophy underlying the teaching and assessment of the subject in Grade 12.
   The purpose of these Examination Guidelines is to:
   • Provide clarity on the depth and scope of the content to be assessed in the Grade 12 National Senior Certificate (NSC) Examination in Physical Sciences.
   • Assist teachers to adequately prepare learners for the examinations.
     This document deals with the final Grade 12 external examinations. It does not deal in any depth with the school-based assessment (SBA).
     
     These Examination Guidelines should be read in conjunction with:
   • The National Curriculum Statement (NCS) Curriculum and Assessment Policy Statement (CAPS): Physical Sciences
   • The National Protocol of Assessment: An addendum to the policy document, the National Senior Certificate: A qualification at Level 4 on the National Qualifications Framework (NQF), regarding the National Protocol for Assessment (Grades R–12)
   • The national policy pertaining to the programme and promotion requirements of the National Curriculum Statement, Grades R–12
2. ASSESSMENT IN GRADE 12
   2.1 Format of question papers

   Paper	Type of questions	Duration	Total	Date	Marking
   1	Physics 10 multiple-choice questions – 20 marks Structured questions – 130 marks	3 hours	150	October/November	External
   2	Chemistry 10 multiple-choice questions – 20 marks Structured questions – 130 marks	3 hours	150	October/November	External

   2.2 Numbering and sequence of questions
   QUESTION 1: Multiple-choice questions
   Subquestions numbered 1.1 to 1.10 (2 marks each)
   Questions may cover all cognitive levels and will be arranged according to topics.
   
   QUESTION 2 onwards:
   Longer questions assessing skills and knowledge across cognitive levels. Numbering starts with QUESTION 2 and will be continuous. Subquestions will be numbered by two digits, e.g. 2.1, 2.2. Numbering is restricted to a maximum of three digits, e.g. 2.1.1, 2.1.2.
   2.3 Information sheets
   The separate information sheets for Paper 1 and Paper 2 are included in this document.
   2.4 Weighting of cognitive levels
   Papers 1 and 2 will include questions across four cognitive levels. The distribution of cognitive levels in Physics and Chemistry papers is given below.

   Cognitive level	Description	Paper 1 (Physics)	Paper 2 (Chemistry)
   1	Remembering (Recall)	15%	15%
   2	Understanding (Comprehension)	35%	40%
   3	Applying and analysing	40%	35%
   4	Evaluating and creating (synthesis)	10%	10%

   2.5 Weighting of prescribed content

   Focus Content	Marks	Total	Duration	Weighting of cognitive levels
   Paper 1: Physics
   Mechanics	65	150 marks	3 hours	15	35	40	10
   Waves, sound and light	15
   Electricity and magnetism	55
   Matter and materials	15
   Paper 2: Chemistry Focus
   Chemical change	92	150 marks	3 hours	15	40	35	10
   Matter and materials	58

   2.6 Skills in Physical Sciences
   • Identify and question phenomena:
   • Formulate an investigative question.
   • List all possible variables.
   • Formulate a testable hypothesis.
     
     Design/Plan of an investigation:
   • Identify variables (dependent, independent and controlled variables).
   • List appropriate apparatus.
   • Plan the sequence of steps which should include, amongst others:
   • The need for more than one trial to minimise experimental errors.
   • Identify safety precautions that need to be taken.
   • Identify conditions that ensure a fair test.
   • Set an appropriate control.
     
     Graphs:
   • Draw accurate graphs from given data/information.
   • Interpret graphs.
   • Draw sketch graphs from given information.
     
     Results:
   • Identify patterns/relationships in data.
   • Interpret results.
     
     Conclusions:
   • Draw conclusions from given information, e.g. tables, graphs.
   • Evaluate the validity of conclusions.
     
     Calculations:
   • Solve problems using two or more different calculations (multistep calculations).
     
     Descriptions:
   • Explain/Describe/Argue the validity of a statement/event using scientific principles.
     
     2.7 Prior knowledge from Grades 10 and 11
     All skills and application of knowledge learnt in Grades 10 and 11 are applicable to assessment in Grade 12. In addition to content from Grades 10 and 11 included under examinable content for Grade 12, skills and knowledge from Grades 10 and 11 that may be assessed in Grade 12 include the following:
   • The use of equations of motion in solving problems dealing with momentum, vertical projectile motion, work, energy and power
   • Sound waves and properties of sound
   • Electromagnetism
     NOTE: Although there will be no direct questions about these aspects, applications thereof can be assessed.
3. ELABORATION OF THE CONTENT
   The final examination in Physical Sciences will cover the topics outlined below.
   3.1 Paper 1: Physics

   Newton's Laws and Application of Newton's Laws (This section must be read in conjunction with the CAPS, p. 62–66.)

   
   Different kinds of forces: weight, normal force, frictional force, applied force (push, pull), tension (strings or cables)
   • Define normal force, N, as the force or the component of a force which a surface exerts on an object with which it is in contact, and which is perpendicular to the surface.
   • Define frictional force, f, as the force that opposes the motion of an object and which acts parallel to the surface.
     Define static frictional force, fs, as the force that opposes the tendency of motion of a stationary object relative to a surface.
     Define kinetic frictional force, fk, as the force that opposes the motion of a moving object relative to a surface.
     Know that a frictional force:
     • Is proportional to the normal force
     • Is independent of the area of contact
     • Is independent of the velocity of motion
   • Solve problems using f_s^max = μsN where f_s^max is the maximum static frictional force and μs is the coefficient of static friction.
     NOTE:
   • If a force, F, applied to a body parallel to the surface does not cause the object to move, F is equal in magnitude to the static frictional force.
   • The static frictional force is a maximum (f_s^max) just before the object starts to move across the surface.
   • If the applied force exceeds f_s^max , a resultant net force accelerates the object.
   • Solve problems using f_k = μ_kN, where f_k is the kinetic frictional force and μ_k the coefficient of kinetic friction.
     
     Force diagrams, free-body diagrams
   • Draw force diagrams.
   • Draw free-body diagrams. (This is a diagram that shows the relative magnitudes and directions of forces acting on a body/particle that has been isolated from its surroundings.)
   • Resolve two-dimensional forces (such as the weight of an object on an inclined plane) into its parallel (x) and perpendicular (y) components.
   • Determine the resultant or net force of two or more forces.
     
     Newton's first, second and third laws of motion
   • State Newton's first law of motion: A body will remain in its state of rest or motion at constant velocity unless a non-zero resultant/net force acts on it.
   • Discuss why it is important to wear seatbelts using Newton's first law of motion.
   • State Newton's second law of motion: When a net force acts on an object, the object will accelerate in the direction of the force and the acceleration is directly proportional to the force and inversely proportional to the mass of the object.
   • Draw force diagrams and free-body diagrams for objects that are in equilibrium or accelerating.
   • Apply Newton's laws to a variety of equilibrium and non-equilibrium problems including:
     • A single object:
       • Moving on a horizontal plane with or without friction
       • Moving on an inclined plane with and without friction
       • Moving in the vertical plane (lifts, rockets, etc.)
     • Two-body systems (joined by a light inextensible string) by applying Newton's laws of motion separately to EACH of the bodies:
       • Both on a flat horizontal plane with and without friction
       • One on a horizontal plane with and without friction, and a second hanging vertically from a string over a frictionless pulley
       • Both on an inclined plane with or without friction
       • Both hanging vertically from a string over a frictionless pulley
   • State Newton's third law of motion: When object A exerts a force on object B, object B
     SIMULTANEOUSLY exerts an oppositely directed force of equal magnitude on object A.
   • Identify action-reaction pairs.
   • List the properties of action-reaction pairs.
     
     Newton's Law of Universal Gravitation
   • State Newton's Law of Universal Gravitation: Each body in the universe attracts every other body with a force that is directly proportional to the product of their masses and inversely proportional to the square of the distance between their centres.
   • Solve problems using F = Gm₁m₂
                                                    r²
   • Describe weight as the gravitational force the Earth exerts on any object on or near its surface.
   • Calculate weight using the expression w = mg.
   • Calculate the weight of an object on other planets with different values of gravitational acceleration.
   • Distinguish between mass and weight.
   • Explain weightlessness.

     Momentum and Impulse (This section must be read in conjunction with the CAPS, p. 99–101.)

     Momentum
     • Define momentum as the product of an object's mass and its velocity.
     • Describe linear momentum as a vector quantity with the same direction as the velocity of the object.
     • Calculate the momentum of a moving object using p = mv.
     • Describe the vector nature of momentum and illustrate it with some simple examples.
     • Draw vector diagrams to illustrate the relationship between the initial momentum, the final momentum and the change in momentum for each of the cases above.
       
       Newton's second law in terms of momentum
     • State Newton's second law of motion in terms of momentum: The net (or resultant) force acting on an object is equal to the rate of change of momentum of the object in the direction of the net force.
     • Express Newton's second law of motion in symbols: F_net= ΔP
                                                                                                    Δt
     • Explain the relationship between net force and change in momentum for a variety of motions.
     • Calculate the change in momentum when a resultant/net force acts on an object and its velocity:
     • Increases in the direction of motion, e.g. 2nd stage rocket engine fires
     • Decreases, e.g. brakes are applied
     • Reverses its direction of motion, e.g. a soccer ball kicked back in the direction it came from
       
       Impulse
     • Define impulse as the product of the resultant/net force acting on an object and the time the net force acts on the object.
     • Use the impulse-momentum theorem, FnetΔt = mΔv, to calculate the resultant/net force exerted, the time for which the force is applied and the change in momentum for a variety of situations involving the motion of an object in one dimension.
     • Explain how the concept of impulse applies to safety considerations in everyday life, e.g. airbags, seatbelts and arrestor beds.
       
       Conservation of momentum and elastic and inelastic collisions
     • Explain what is meant by a system (in Physics).
     • Explain (when working with systems) what is meant by internal and external forces.
     • Explain what is meant by an isolated system (in Physics), i.e. a system on which the net
       external force is zero.
       (An isolated system excludes external forces that originate outside the colliding bodies, e.g. friction. Only internal forces, e.g. contact forces between the colliding objects, are considered.)
     • State the principle of conservation of linear momentum: The total linear momentum of an isolated system remains constant (is conserved).
     • Apply the conservation of momentum to the collision of two objects moving in one dimension (along a straight line) with the aid of an appropriate sign convention.
     • Distinguish between elastic collisions and inelastic collisions by calculation.

     Vertical Projectile Motion in One Dimension (1D) (This section must be read in conjunction with the CAPS, p. 102–103.)

     • Explain what is meant by a projectile, i.e. an object which has been given an initial velocity and then it moves under the influence of the gravitational force only.
     • Define free fall as motion during which the only force acting on an object is the gravitational force.
     • Use equations of motion to determine the position, velocity and displacement of a projectile at any given time.
     • Sketch position versus time (x vs. t), velocity versus time (v vs. t) and acceleration versus time (a vs. t) graphs for:
       • A free-falling object
       • An object thrown vertically upwards
       • An object thrown vertically downwards
       • Bouncing objects (restricted to balls)
     • For a given x vs. t, v vs. t or a vs. t graph, determine:
       • Position
       • Displacement
       • Velocity or acceleration at any time t
     • For a given x vs. t, v vs. t or a vs. t graph, describe the motion of the object:
       • Bouncing
       • Thrown vertically upwards
       • Thrown vertically downward

     Work, Energy and Power (This section must be read in conjunction with the CAPS, p. 117–120.)

     Work
     • Define the work done on an object by a constant force F as FΔx cos θ , where F is the magnitude of the force, Δx the magnitude of the displacement and  the angle between the force and the displacement. (Work is done by a force – the use of the term 'work is done against a force', e.g. work done against friction, must be avoided.)
     • Draw a force diagram and free-body diagrams.
     • Calculate the net work done on an object.
     • Distinguish between positive net work done and negative net work done on the system.
       
       Work-energy theorem
     • State the work-energy theorem: The work done on an object by a net force is equal to the change in the object's kinetic energy OR the work done on an object by a net force is equal to the change in the object's kinetic energy.
       In symbols: W_net = Δ K = K_f - K_i
     • Apply the work-energy theorem to objects on horizontal, vertical and inclined planes (for both frictionless and rough surfaces).
       
       Conservation of energy with non-conservative forces present
     • Define a conservative force as a force for which the work done in moving an object between two points is independent of the path taken. Examples are gravitational force, the elastic force in a spring and electrostatic forces (coulombic forces).
     • Define a non-conservative force as a force for which the work done in moving an object between two points depends on the path taken. Examples are frictional force, air resistance, tension in a chord, etc.
     • State the principle of conservation of mechanical energy: The total mechanical energy (sum of gravitational potential energy and kinetic energy) in an isolated system remains constant. NOTE: A system is isolated when the net external force (excluding the gravitational force) acting on the system is zero.
     • Solve conservation of energy problems using the equation: W_nc = ΔE_k + ΔE_p
     • Use the relationship above to show that in the absence of non-conservative forces, mechanical energy is conserved.
       
       Power
     • Define power as the rate at which work is done or energy is expended.
       In symbols: P = W
                                 Δt
     • Calculate the power involved when work is done.
     • Perform calculations using Pave= Fvave when an object moves at a constant speed along a rough horizontal surface or a rough inclined plane.
     • Calculate the power output for a pump lifting a mass (e.g. lifting water through a height at constant speed).

     Doppler Effect (relative motion between source and observer) (This section must be read in conjunction with the CAPS, p. 121–122.)

     With sound and ultrasound
     • State the Doppler effect as the change in frequency (or pitch) of the sound detected by a listener, because the sound source and the listener have different velocities relative to the medium of sound propagation.
     • Explain (using appropriate illustrations) the change in pitch observed when a source moves toward or away from a listener.
     • Solve problems using the equation f_L = V±V_L f_s  when EITHER the source OR the listener is moving.
                                                                      V±V_s 
     • State applications of the Doppler effect.
       
       With light – red shifts in the universe (evidence for the expanding universe)
     • Explain red shifts.
     • Use the Doppler effect to explain why we conclude that the universe is expanding.

     Electrostatics (This section must be read in conjunction with the CAPS, p. 84–85.)

     Coulomb's law
     • State Coulomb's law: The magnitude of the electrostatic force exerted by one point charge (Q1) on another point charge (Q2) is directly proportional to the product of the magnitudes of the charges and inversely proportional to the square of the distance (r) between them:
     • Solve problems using the equation F = kQ₁Q₂ for charges in one dimension (1D) (restrict to three charges).
                                                                         r²
     • Solve problems using the equation F = kQ₁Q₂ 
                                                                           r²       for charges in two dimensions (2D) – for three charges in a right-angled formation (limit to charges at the 'vertices of a right-angled triangle').                         
       
       Electric field
     • Describe an electric field as a region of space in which an electric charge experiences a force. The direction of the electric field at a point is the direction that a positive test charge would move if placed at that point.
     • Draw electric field lines for the following configurations:
       • A single point charge
       • Two point charges (one negative, one positive OR both positive OR both negative)
       • A charged sphere
     • NOTE: Restrict to situations in which the charges are identical in magnitude.
     • Define electric field at a point: The electric field at a point is the electrostatic force experienced per unit positive charge placed at that point. In symbols: E = F
                            q                                                                                                                                                                                             
     • Solve problems using the equation E = F
                                                                      q
     • Calculate the electric field at a point due to a number of point charges, using the equation E = kQ 
                                                                                                                                                              r²    to determine the contribution to the field due to each charge. Restrict to three charges in a straight line.

     Electric Circuits (This section must be read in conjunction with the CAPS, p. 88–89 & 121.)

     Ohm's law
     • State Ohm's law in words: The potential difference across a conductor is directly proportional to the current in the conductor at constant temperature.
     • Determine the relationship between current, potential difference and resistance at constant temperature using a simple circuit.
     • State the difference between ohmic conductors and non-ohmic conductors and give an example of each.
     • Solve problems using R = V  for series and parallel circuits (maximum four resistors).
                                                   I
     • Power, energy
     • Define power as the rate at which work is done.
     • Solve problems using P = W
                                                 Δt
     • Solve problems using P = VI , P = I²R or P = V²
                                                                               R
     • Solve circuit problems involving the concepts of power and electrical energy.
     • Deduce that the kilowatt hour (kWh) refers to the use of 1 kilowatt of electricity for 1 hour.
     • Calculate the cost of electricity usage given the power specifications of the appliances used, the duration and the cost of 1 kWh.
       
       Internal resistance, series and parallel networks
     • Solve problems involving current, voltage and resistance for circuits containing arrangements of resistors in series and in parallel (maximum four resistors excluding internal resistance).
     • Define the term emf as the maximum energy provided by a battery per unit charge passing through it.
     • Solve circuit problems using ε = V_load + V_{internal resistance} or ε =IR_ext+ Ir.
     • Solve circuit problems, with internal resistance, involving series-parallel networks of resistors (maximum four resistors).

     Electrodynamics (This section must be read in conjunction with the CAPS, p. 130–131.)

     • Electrical machines (generators, motors)
     • State the energy conversion in generators.
     • Use the principle of electromagnetic induction to explain how a generator works.
     • Explain the functions of the components of an AC and a DC generator.
     • State examples of the uses of AC and DC generators.
     • State the energy conversion in motors.
     • Use the motor effect to explain how a motor works.
     • Explain the functions of the components of a motor.
     • State examples of the use of motors.
       
       Alternating current
     • State the advantages of alternating current over direct current.
     • Sketch graphs of voltage versus time and current versus time for an AC circuit.
     • Define the term rms for an alternating voltage/current.
       The rms potential difference is the AC potential difference which dissipates/produces the same amount of energy as an equivalent DC potential difference.
       The rms current is the alternating current which dissipates/produces the same amount of energy as an equivalent direct current (DC).
     • Solve problems using I_rms = I_max,V_rms = V_max
                                                       √2                    √2
       
     • Solve problems using P_ave = I_rmsV_rms = ½ I_maxV_max (for a purely resistive circuit), P_ave = I²_rmsRand P_ave = V²_rms
                                                                                                                                                                                      R

     Optical Phenomena and Properties of Materials (This section must be read in conjunction with the CAPS, p. 132–133.)

     Photo-electric effect
     • Describe the photoelectric effect as the process whereby electrons are ejected from a metal surface when light of suitable frequency is incident on that surface.
     • State the significance of the photoelectric effect.
     • Define threshold frequency, fo, as the minimum frequency of light needed to emit electrons from a certain metal surface.
     • Define work function, Wo, as the minimum energy that an electron in the metal needs to be emitted from the metal surface.
     • Perform calculations using the photoelectric equation:
       E =W_o+ E_k(max), where E = hf and W_o= hf_o and E_k(max) = ½ mv²_max
     • Explain the effect of intensity and frequency on the photoelectric effect.
     • State that the photoelectric effect demonstrates the particle nature of light.
       
       Emission and absorption spectra
     • Explain the formation of atomic spectra by referring to energy transition.
     • Explain the difference between atomic absorption and emission spectra. An atomic absorption spectrum is formed when certain frequencies of electromagnetic radiation passing through a substance is absorbed.
       For example, when light passes through a cold gas, atoms in the gas absorb characteristic frequencies of the light and the spectrum observed is a continuous spectrum with dark lines where characteristic frequencies of light were removed. The frequencies of the absorption lines are unique to the type of atoms in the gas.
       An atomic emission spectrum is formed when certain frequencies of e lectromagnetic radiation are emitted due to an atom making a transition from a higher energy state to a lower energy state. For example, atoms in a hot gas emit light at characteristic frequencies. The spectrum observed is a line spectrum with only a few coloured lines of frequencies unique to the type of atom that is producing the emission lines.
       3.2 Paper 2: Chemistry

     Representing Chemical Change (This section must be read in conjunction with the CAPS, p. 37.)

     Balanced chemical equations
     • Write and balance chemical equations.
     • Interpret balanced reaction equations in terms of:
     • Conservation of atoms
     • Conservation of mass (use relative atomic masses)

     Quantitative Aspects of Chemical Change (This section must be read in conjunction with the CAPS, p. 82.)

     Molar volume of gases
     • 1 mole of any gas occupies 22,4 dm3 at 0 °C (273 K) and 1 atmosphere (101,3 kPa).
       Volume relationships in gaseous reactions
     • Interpret balanced equations in terms of volume relationships for gases, i.e. under the same conditions of temperature and pressure, equal number of moles of all gases occupy the same volume.
       
       Concentration of solutions
     • Calculate the molar concentration of a solution.
       
       More complex stoichiometric calculations
     • Determine the empirical formula and molecular formula of compounds.
     • Determine the percentage yield of a chemical reaction.
     • Determine percentage purity or percentage composition, e.g. the percentage CaCO3 in an impure sample of seashells.
     • Perform stoichiometric calculations based on balanced equations.
     • Perform stoichiometric calculations based on balanced equations that may include limiting reagents.

     Intermolecular Forces (This section must be read in conjunction with the CAPS, p. 71–73.)

     Intermolecular and interatomic forces (chemical bonds)
     • 1. Name and explain the different intermolecular forces (Van der Waal's forces):
       2. Dipole-dipole forces:
          Forces between two polar molecules
          Induced dipole forces or London forces:
          Forces between non-polar molecules
       3. Hydrogen bonding:
          Forces between molecules in which hydrogen is covalently bonded to nitrogen, oxygen or fluorine – a special case of dipole-dipole forces
     • Describe the difference between intermolecular forces and interatomic forces (intramolecular forces) using a diagram of a group of small molecules; and in words.
       
     • State the relationship between intermolecular forces and molecular size. For non-polar molecules, the strength of induced dipole forces increases with molecular size.
     • Explain the effect of intermolecular forces on boiling point, melting point and vapour pressure.
       Boiling point:
       The temperature at which the vapour pressure of a substance equals atmospheric pressure. The stronger the intermolecular forces, the higher the boiling point.
       Melting point:
       The temperature at which the solid and liquid phases of a substance are at equilibrium. The stronger the intermolecular forces, the higher the melting point.
       Vapour pressure:
       The pressure exerted by a vapour at equilibrium with its liquid in a closed system. The stronger the intermolecular forces, the lower the vapour pressure.

     Organic Molecules (This section must be read in conjunction with the CAPS, p. 104–116.)

     Define organic molecules as molecules containing carbon atoms.
     Organic molecular structures – functional groups, saturated and unsaturated structures, isomers
     • Write down condensed structural formulae, structural formulae, molecular formulae and IUPAC names (up to 8 carbon atoms) for:
     • Alkanes (no ring structures)
     • Alkenes (no ring structures)
     • Alkynes
     • Halo-alkanes (primary, secondary and tertiary haloalkanes; no ring structures)
     • Alcohols (primary, secondary and tertiary alcohols)
     • Carboxylic acids
     • Esters
     • Aldehydes
     • Ketones
       
       Know the following definitions/terms:
     • Molecular formula: A chemical formula that indicates the element and numbers of each of the atoms in a molecule.
       Example: C₄H₈O
     • Structural formula: A structural formula of a compound shows which atoms are attached to which within the molecule. Atoms are represented by their chemical symbols and lines are used to represent ALL the bonds that hold the atoms together.
       Example:
     • Condensed structural formula: This notation shows the way in which atoms are bonded together in the molecule, but DOES NOT SHOW ALL bond lines.
       Example:
       CH₃CH₂COCH₃OR 
     • Hydrocarbon: Organic compounds that consist of hydrogen and carbon only.
     • Homologous series: A series of organic compounds that can be described by the same general formula OR in which one member differs from the next with a CH2 group
     • Saturated compounds: Compounds in which there are no multiple bonds between C atoms in their hydrocarbon chains
     • Unsaturated compounds: Compounds with one or more multiple bonds between C atoms in their hydrocarbon chains
     • Functional group: A bond or an atom or a group of atoms that determine(s) the physical and chemical properties of a group of organic compounds

     Homologous series	Structure of functional group
     	Structure	Name/Description
     Alkanes		Only C-H and C-C single bonds
     Alkenes		Carbon-carbon double bond
     Alkynes		Carbon-carbon triple bond
     Haloalkanes		Halogen atom bonded to a C atom in an alkane
     Alcohols		Hydroxyl group bonded to a saturated C atom
     Aldehydes		Formyl group
     Ketones		Carbonyl group bonded to two C atoms
     Carboxylic acids		Carboxyl group
     Esters		-

     • Structural isomer: Organic molecules with the same molecular formula, but different structural formulae
     • Identify compounds (up to 8 carbon atoms) that are saturated, unsaturated and are structural isomers.
     • Restrict structural isomers to chain isomers, positional isomers and functional isomers.
       • Chain isomers: Same molecular formula, but different types of chains, e.g. butane and 2-methylpropane
         
       • Positional isomers: Same molecular formula, but different positions of the side chain, substituents or functional groups on the parent chain, e.g. 1 chloropropane and 2-chloropropane or but-2-ene and but-1-ene
         
       • Functional isomers: Same molecular formula, but different functional groups, e.g. methyl methanoate and ethanoic acid
         
         
         IUPAC naming and formulae for compounds in the homologous series above
     • Write down the IUPAC name when given the structural formula or condensed structural formula.
     • Write down the structural formula when given the IUPAC name or molecular formula.
     • Compounds must be restricted to one functional group per compound (except haloalkanes).
     • Haloalkanes restricted to two functional groups per compound.
     • Alkyl substituents (methyl- and ethyl- only) restricted to a maximum of THREE on the parent chain.
     • When naming haloalkanes:
       • Halogen substituents do not get preference over alkyl groups.
       • Numbering should start from the end nearest to the first substituent.
       • When substituents, e.g. Br and Cℓ or Cℓ and methyl, have the same number when numbered from different ends of chain, preference is given to alphabetical order,
         e.g. bromo- over chloro-; chloro- over methyl-.
       • When writing IUPAC names, substituents are written alphabetically namely bromo, chloro, ethyl, methyl. Ignore prefixes di and tri.
         
         Structure and physical properties (boiling point, melting point, vapour pressure) relationships
     • For a given example (from the above functional groups), explain the relationship between physical properties and:
       • Strength of intermolecular forces (Van der Waal's forces), i.e. hydrogen bonds, dipole-dipole forces, induced dipole forces
       • Type of functional groups
       • Chain length
       • Branched chains
     • Oxidation of alkanes
     • State the use of alkanes as fuels.
     • Write down an equation for the combustion of an alkane in excess oxygen.
       
       Esterification
     • Write down an equation, using structural formulae or condensed structural formulae, for the formation of an ester.
     • Name the alcohol and carboxylic acid used and the ester formed.
     • Write down reaction conditions for esterification.
       
       Substitution, addition and elimination reactions
     • Identify reactions as elimination, substitution or addition.
     • Write down, using structural formulae or condensed structural formulae, equations and reaction conditions for the following addition reactions of alkenes:
       • Hydrohalogenation:
         The addition of a hydrogen halide to an alkene
       • Halogenation:
         The reaction of a halogen (Br₂, Cℓ₂) with a compound
       • Hydration:
         The addition of water to a compound
       • Hydrogenation:
         The addition of hydrogen to an alkene
     • Identify major and minor products in the above addition reactions.
     • Write down, using structural formulae or condensed structural formulae, equations and reaction conditions for the following elimination reactions:
       • Dehydrohalogenation of haloalkanes:
         The elimination of hydrogen and a halogen from a haloalkane
       • Dehydration of alcohols:
         Elimination of water from an alcohol
       • Cracking of alkanes:
         The chemical process in which longer chain hydrocarbon molecules are broken down to shorter more useful molecules.
     • Identify major and minor products in the above elimination reactions.
     • Write down, using structural formulae or condensed structural formulae, equations and reaction conditions for the following substitution reactions:
       • Hydrolysis of haloalkanes
         Hydrolysis: The reaction of a compound with water
       • Reactions of HX (X = Cℓ, Br) with alcohols to produce haloalkanes
       • Halogenation of alkanes
         The reaction of a halogen (Br₂, Cℓ₂) with a compound
     • Distinguish between saturated and unsaturated hydrocarbons using bromine water.
       

       Energy and Change (This section must be read in conjunction with the CAPS, p. 90–91.)

       Energy changes in reactions related to bond energy changes
     • Define heat of reaction (ΔH) as the energy absorbed or released in a chemical reaction.
     • Define exothermic reactions as reactions that release energy.
     • Define endothermic reactions as reactions that absorb energy.
     • Classify (with reason) reactions as exothermic or endothermic.
       
       Exothermic and endothermic reactions
     • State that ΔH > 0 for endothermic reactions, i.e. reactions in which energy is absorbed.
     • State that ΔH < 0 for exothermic reactions, i.e. reactions in which energy is released.
       
       Activation energy
     • Define activation energy as the minimum energy needed for a reaction to take place.
     • Define an activated complex as the unstable transition state from reactants to products.
     • Draw or interpret fully labelled sketch graphs (potential energy versus course of reaction graphs) of catalysed and uncatalysed endothermic and exothermic reactions.
       

       Rate and Extent of Reaction (This section must be read in conjunction with the CAPS, p. 123–124.)

       Rates of reaction and factors affecting rate
     • Define reaction rate as the change in concentration of reactants or products per unit time.
     • Calculate reaction rate from given data for reactants:
       Rate = Δc (Unit: mol∙dm^-3∙s^-1)
                   Δt
       Calculate reaction rate from given data for products:
       Rate =  Δc (Unit: mol∙dm^-3∙s^-1)
                    Δt
       Questions may also include calculations of rate in terms of change in mass/volume/ moles per time.
     • List the factors that affect the rate of chemical reactions, i.e. nature of reacting substances, surface area, concentration (pressure for gases), temperature and the presence of a catalyst.
     • Explain in terms of the collision theory how the various factors affect the rate of chemical reactions. The collision theory is a model that explains reaction rate as the result of particles colliding with a certain minimum energy to form products.
       
       Measuring rates of reaction
     • Answer questions and interpret data (tables or graphs) on different experimental techniques for measuring the rate of a given reaction.
       
       Mechanism of reaction and of catalysis
     • Define the term catalyst as a substance that increases the rate of a chemical reaction without itself undergoing a permanent change.
     • Explain that a catalyst increases the rate of a reaction by providing an alternative path of lower activation energy. It therefore decreases the net activation energy.
     • Interpret Maxwell-Boltzmann curves (number of particles against kinetic energy) to explain the effect of a catalyst, temperature and concentration on reaction rate.

     Chemical Equilibrium (This section must be read in conjunction with the CAPS, p. 125–126.)

     Chemical equilibrium and factors affecting equilibrium
     • Explain what is meant by:
     • Open and closed systems: An open system continuously interacts with its environment, while a closed system is isolated from its surroundings.
     • A reversible reaction: A reaction is reversible when products can be converted back to reactants and vice versa.
     • Chemical equilibrium: It is a dynamic equilibrium when the rate of the forward reaction equals the rate of the reverse reaction.
     • List the factors that influence the position of an equilibrium, i.e. pressure (gases only), concentration and temperature.
       
       Equilibrium constant
     • List the factors that influence the value of the equilibrium constant, Kc.
     • Write down an expression for the equilibrium constant, having been given the equation for the reaction.
     • Perform calculations based on Kc values.
     • Explain the significance of high and low values of the equilibrium constant.
       
       Application of equilibrium principles
     • State Le Chatelier's principle: When the equilibrium in a closed system is disturbed, the system will re-instate a new equilibrium by favouring the reaction that will oppose the disturbance.
     • Use Le Chatelier's principle to explain changes in equilibria qualitatively.
     • Interpret graphs of equilibrium, e.g. concentration/rate/number of moles/mass/ volume versus time.

     Acids and Bases (This section must be read in conjunction with the CAPS, p. 127–128.)

     Acid-base reactions
     • Define acids and bases according to Arrhenius and Lowry-Brønsted theories:
       Arrhenius theory: Acids produce hydrogen ions (H⁺/H₃O+/hydronium ions) in aqueous solution. Bases produce hydroxide ions (OH^-) in aqueous solution.
       Lowry-Brønsted theory: An acid is a proton (H⁺ ion) donor. A base is a proton (H⁺ ion) acceptor.
       
       Relative strengths of acids and bases
     • Distinguish between strong acids/bases and weak acids/bases with examples.
       Strong acids ionise completely in water to form a high concentration of H₃O⁺ ions. Examples of strong acids are hydrochloric acid, sulphuric acid and nitric acid.
       Weak acids ionise incompletely in water to form a low concentration of H₃O+ ions. Examples of weak acids are ethanoic acid and oxalic acid.
       Strong bases dissociate completely in water to form a high concentration of OH- ions.
       Examples of strong bases are sodium hydroxide and potassium hydroxide.
       Weak bases dissociate/ionise incompletely in water to form a low concentration of OH^- ions.
       Examples of weak bases are ammonia, calcium carbonate, potassium carbonate, calcium carbonate and sodium hydrogen carbonate.
     • Distinguish between concentrated acids/bases and dilute acids/bases.
       Concentrated acids/bases contain a large amount (number of moles) of acid/base in proportion to the volume of water.
       Dilute acids/bases contain a small amount (number of moles) of acid/base in proportion to the volume of water.
       
       Acid-base reactions
     • Write down the reaction equations of aqueous solutions of acids and bases.
       Examples: HCℓ(g) + H₂O(ℓ) → H₃O⁺(aq) + Cℓ-(aq) (HCℓ is a monoprotic acid.)
       NH₃(g) + H₂O(ℓ) → NHm⁺₄(aq) + OH^-(aq)
       H₂SO₄(aq) + 2H₂O(ℓ) → 2H₃O⁺(aq) + SO2^2-₄(aq) (H₂SO₄ is a diprotic acid.)
     • Identify conjugate acid-base pairs for given compounds.
     • Describe a substance that can act as either acid or base as ampholyte. Water is a good example of an ampholyte substance. Write equations to show how an ampholyte substance can act as acid or base.
     • Write down neutralisation reactions of common laboratory acids and bases.
       Examples: HCℓ(aq) + NaOH(aq)/KOH(aq) → NaCℓ(aq)/KCℓ(aq) + H₂O(ℓ)
       HCℓ(aq) + Na₂CO₃(aq) → NaCℓ(aq) + H₂O(ℓ) + CO₂(g)
       HNO₃(aq) + NaOH(aq) → NaNO₃(aq) + H₂O(ℓ)
       H₂SO₄(aq) + 2NaOH(aq) → Na₂SO₄(aq) + 2H₂O(ℓ)
       (COOH)₂(aq) + NaOH(aq) → (COO)₂Na2(aq) + H₂O(ℓ)
       CH₃COOH(aq) + NaOH(aq) → CH₃COONa(aq) + H₂O(ℓ)
       NOTE: The above are examples of equations that learners will be expected to write from given information. However, any other neutralisation reaction can be given in the question paper to assess, e.g. stoichiometry.
       
       Hydrolysis
     • Define hydrolysis as the reaction of a salt with water.
     • Determine the approximate pH (equal to, smaller than or larger than 7) of salts in salt hydrolysis.
       • Hydrolysis of the salt of a weak acid and a strong base results in an alkaline solution, i.e. the pH > 7. Examples of such salts are sodium ethanoate, sodium oxalate and sodium carbonate.
       • Hydrolysis of the salt of a strong acid and a weak base results in an acidic solution, i.e. the pH < 7. An example of such a salt is ammonium chloride.
       • The salt of a strong acid and a strong base does not undergo hydrolysis and the solution of the salt will be neutral, i.e. pH = 7.
         
         Acid-base titrations
     • Motivate the choice of a specific indicator in a titration. Choose from methyl orange, phenolphthalein and bromothymol blue.
     • Define the equivalence point of a titration as the point at which the acid/base has completely reacted with the base/acid.
       Define the endpoint of a titration as the point where the indicator changes colour.
     • Perform stoichiometric calculations based on titrations of a strong acid with a strong base, a strong acid with a weak base and a weak acid with a strong base. Calculations may include percentage purity.
     • For a titration, e.g. the titration of oxalic acid with sodium hydroxide:
       • List the apparatus needed or identify the apparatus from a diagram.
       • Describe the procedure to prepare a standard oxalic acid solution.
       • Describe the procedure to conduct the titration.
       • Describe safety precautions.
       • Describe measures that need to be in place to ensure reliable results.
       • Interpret given results to determine the unknown concentration.
         
         pH and the pH scale
     • Explain the pH scale as a scale of numbers from 0 to 14 used to express the acidity or alkalinity of a solution.
     • Calculate pH values of strong acids and strong bases using pH = -log[H₃O⁺].
     • Define K_w as the equilibrium constant for the ionisation of water or the ion product of water or the ionisation constant of water, i.e. K_w = [H₃O+][OH^-] = 1 x 1014 by 298 K.
     • Explain the auto-ionisation of water, i.e. the reaction of water with itself to form H₃O⁺ ions and OH^- ions.
     • Interpret K_a values of acids to determine the relative strength of given acids. Interpret Kb values of bases to determine the relative strength of given bases.
     • Compare strong and weak acids by looking at:
       • pH (monoprotic and diprotic acids)
       • Conductivity
       • Reaction rate

     Electrochemical Reactions (This section must be read in conjunction with the CAPS, p. 134–137.)

     Galvanic cells
     • Define the galvanic cell as a cell in which chemical energy is converted to electrical energy.
     • Define oxidation and reduction in terms of electron (e-) transfer:
       Oxidation is a loss of electrons. Reduction is a gain of electrons.
     • Define oxidation and reduction in terms of oxidation numbers:
       Oxidation: an increase in oxidation number
       Reduction: a decrease in oxidation number
     • Define an oxidising agent and a reducing agent in terms of oxidation and reduction:
       Oxidising agent: a substance that is reduced/gains electrons.
       Reducing agent: a substance that is oxidised/loses electrons.
     • Define an anode and a cathode in terms of oxidation and reduction:
       Anode: the electrode where oxidation takes place
       Cathode: the electrode where reduction takes place
     • Define an electrolyte as a substance of which the aqueous solution contains ions OR a substance that dissolves in water to give a solution that conducts electricity.
       
       Relation of current and potential difference to rate and equilibrium
     • State that the potential difference of a galvanic cell (Vcell) is related to the extent to which the spontaneous cell reaction has reached equilibrium.
     • State and use the qualitative relationship between Vcell and the concentration of product ions and reactant ions for the spontaneous reaction, namely Vcell decreases as the concentration of product ions increases and the concentration of reactant ions decreases until equilibrium is reached at which the Vcell = 0 (the cell is 'flat'). (Qualitative only. Nernst equation is NOT required.)
       Understanding of the processes and redox reactions taking place in galvanic cells
     • Describe the movement of ions in the solutions.
     • State the direction of electron flow in the external circuit.
     • Write down the half-reactions that occur at the electrodes.
     • State the function of the salt bridge.
     • Use cell notation or diagrams to represent a galvanic cell.
       When writing cell notation, the following convention should be used:
       • The H₂|H⁺ half-cell is treated just like any other half-cell.
       • Cell terminals (electrodes) are written on the outside of the cell notation.
       • Active electrodes: reducing agent | oxidised species || oxidising agent | reduced species
       • Inert electrodes (usually Pt or C):
       • Pt | reducing agent | oxidised species || oxidising agent | reduced species | Pt
         Example: Pt | Cℓ-(aq) |Cℓ2(g) || F₂(g) | F-(aq) | Pt
     • Predict the half-cell in which oxidation will take place when two half-cells are connected.
     • Predict the half-cell in which reduction will take place when connected to another half-cell.
     • Write down the overall cell reaction by combining two half-reactions.
     • Use the Table of Standard Reduction Potentials to calculate the emf of a standard galvanic cell.
     • Use a positive value of the standard emf as an indication that the reaction is spontaneous under standard conditions.
       
       Standard electrode potentials
     • Write down the standard conditions under which standard electrode potentials are determined.
     • Describe the standard hydrogen electrode and explain its role as the reference electrode.
     • Explain how standard electrode potentials can be determined using the reference electrode and state the convention regarding positive and negative values.
       
       Electrolytic cells
     • Define the electrolytic cell as a cell in which electrical energy is converted into chemical energy
     • Electrolysis: The chemical process in which electrical energy is converted to chemical energy OR the use of electrical energy to produce a chemical change
       
       Understanding the processes and redox reactions taking place in electrolytic cells
     • Describe the movement of ions in the solution.
     • State the direction of electron flow in the external circuit.
     • Write equations for the half-reactions taking place at the anode and cathode.
     • Write down the overall cell reaction by combining two half-reactions.
     • Describe, using half-reactions and the equation for the overall cell reaction as well as the layout of the particular cell using a schematic diagram, the following electrolytic processes:
       • The decomposition of copper(II) chloride
       • Electroplating, e.g. the electroplating of an iron spoon with silver/nickel
       • Refining of metals, e.g. copper
       • The electrolysis of a concentrated solution of sodium chloride
4. GENERAL INFORMATION
   4.1 Quantities, symbols and units
   The most common quantities, symbols and SI units used in introductory Physics are listed below.
   A quantity should not be confused with the unit in which it is measured

   Quantity	Preferred symbol	Alternative symbol	Unit name	Unit symbol
   mass	m		kilogram	kg
   position	x,y		metre	m
   displacement	Δx, Δy	s	metre	m
   velocity	vx, vy	u,v	metre per second	m·s-1
   initial velocity	vi	u	metre per second	m·s-1
   final velocity	vf	v	metre per second	m·s-1
   acceleration	a		metre per second per second	m·s-2
   acceleration due to gravity	g		metre per second per second	m·s-2
   time (instant)	t		second	s
   time interval	Δt		second	s
   energy	E		joule	J
   kinetic energy	K	Ek	joule	J
   potential energy	U	Ep	joule	J
   work	W		joule	J
   work function	W0		joule	J
   power	P		watt	W
   momentum	p		kilogram metre per second	kg·m·s-1
   force	F		newton	N
   weight	w	Fg	newton	N
   normal force	N	FN	newton	N
   tension	T	FT	newton	N
   friction force	f	Ff	newton	N
   coefficient of friction	μ,μs,μk		(none)
   torque	τ		newton metre	N.m
   wavelength	λ		metre	m
   frequency	f	v	hertz per second	Hz or s-1
   period	T		second	s
   speed of light	c		metre per second	m·s-1
   refractive index	n		(none)
   focal length	f		metre	m
   object distance	s	u	metre	m
   image distance	s'	v	metre	m
   magnification	m		(none)
   charge	Q,q		coulomb	C
   electric field	E		newton per coulomb or volt per metre	N·C-1 or V·m-1
   electric potential at point P	VP		volt	V
   potential difference	ΔV, V		volt	V
   emf	E	ε	volt	V
   current	I, i		ampere	A
   resistance	R		ohm	Ω
   internal resistance	r		ohm	Ω
   magnetic field	B		tesla	T
   magnetic flux	Φ		tesla.metre2 or weber	T·m2 or Wb

   Conventions (e.g. signs, symbols, terminology and nomenclature)
   The syllabus and question papers will conform to generally accepted international practices.
   NOTE:
   1. For marking purposes, alternative symbols will also be accepted
   2. Separate compound units with a multiplication dot, not a full stop, e.g m.s^-1 .
      For marking ourposes, m.s^-1 will also be accepted
   3. Use the equal sign only when it is mathematically correct, e.g 
      Incorrect: 1cm=1m (on a scale drawing)
      Correct; 1cm = 10^-2m (1 cm represents 1 m on a scale drawing)
      4.2 Information sheets - Paper 1 (Physics)
      DATA FOR PHYSICAL SCIENCES GRADE 12 PAPER 1 (PHYSICS)
      TABLE 1 ; PHYSICAL CONSTANTS

      NAME	SYMBOL	VALUE
      Acceleration due to gravity	g	9,8 m·s-2
      Universal gravitational constant	G	6,67 x 10-11 N·m2·kg-2
      Speed of light in a vacuum	c	3,0 x 108 m·s-1
      Planck's constant	h	6,63 x 10-34 J·s
      Coulomb's constant	k	9,0 x 109 N·m2·C-2
      Charge on electron	e	-1,6 x 10-19 C
      Electron mass	me	9,11 x 10-31 kg
      Mass of the Earth	M	5,98 x 1024 kg
      Radius of the Earth	RE	6,38 x 106 m

      TABLE 2: FORMULAE
      MOTION
      
      FORCE
      
      WORK, ENERGY AND POWER
      
      WAVES, SOUND AND LIGHT
      
      ELECTROSTATICS
      
      ELECTRIC CIRCUITS
      
      ALTERNATING CURRENT
      
      4.3 Information Sheets – Paper 2 (Chemistry)
      DATA FOR PHYSICAL SCIENCES GRADE 12 PAPER 2 (CHEMISTRY)
      TABLE 1: PHYSICAL CONSTANTS

      NAME	SYMBOL	VALUE
      Standard pressure	pθ	1,013 x 105 Pa
      Molar gas volume at STP	Vm	22,4 dm3∙mol-1
      Standard temperature	Tθ	273 K
      Charge on electron	e	-1,6 x 10-19 C
      Avogadro's constant	NA	6,02 x 1023 mol-1

      TABLE 2 ; FORMULAE
      
      TABLE 3 ; THE PERODIC TABLE OF ELEMENTS
      
      TABLE 4A: STANDARD REDUCTION POTENTIALS
      
      

5. MARKING GUIDELINES: PAPER 1
   5.1 Calculations
   5.1.1 Marks will be awarded for: correct formula, correct substitution, correct answer with unit.
   5.1.2 No marks will be awarded if an incorrect or inappropriate formula is used, even though there may be relevant symbols and applicable substitutions.
   5.1.3 When an error is made during substitution into a correct formula, a mark will be awarded for the correct formula and for the correct substitutions, but no further marks will be given.
   5.1.4 If no formula is given, but all substitutions are correct, the candidate will forfeit one mark.
   5.1.5 No penalisation if zero substitutions are omitted in calculations where correct formula/principle is given correctly.
   5.1.6 Mathematical manipulations and change of subject of appropriate formulae carry no marks, but if a candidate starts off with the correct formula and then changes the subject of the formula incorrectly, marks will be awarded for the formula and the correct substitutions. The mark for the incorrect numerical answer is forfeited.
   5.1.7 Marks are only awarded for a formula if a calculation has been attempted, i.e. substitutions have been made or a numerical answer given.
   5.1.8 Marks can only be allocated for substitutions when values are substituted into formulae and not when listed before a calculation starts.
   5.1.9 All calculations, when not specified in the question, must be rounded off to a minimum of TWO decimal places.
   5.1.10 If a final answer to a calculation is correct, full marks will not automatically be awarded. Markers will always ensure that the correct/appropriate formula is used and that workings, including substitutions, are correct.
   5.1.11 Questions where a series of calculations do not necessarily always have to follow the same order (as in circuit calculations) full marks will be awarded provided that it is a valid solution to the problem.
   5.1.12 Any calculation that will not bring the candidate closer to the answer than the original solution, will not count any marks.
   5.2 Units
   5.2.1 Candidates will only be penalised once for the repeated use of an incorrect unit within a question.
   5.2.2 Units are only required in the final answer to a calculation.
   5.2.3 Marks are only awarded for an answer, and not for a unit per se. Candidates will therefore forfeit the mark allocated for the answer in each of the following situations:

   • Correct answer + wrong unit
   • Wrong answer + correct unit
   • Correct answer + no unit

   5.2.4 SI units must be used, except in certain cases, e.g. V∙m^-1 instead of N∙C^-1, and cm∙s^-1 or km∙h^-1 instead of m∙s^-1 where the question warrants this.
   5.3 General
   5.3.1 If one answer or calculation is required, but two are given by the candidate, only the first one will be marked, irrespective of which one is correct. If two answers are required, only the first two will be marked, etc.
   5.3.2 For marking purposes, alternative symbols (s, u, t, etc.) will also be accepted.
   5.3.3 Separate compound units with a multiplication dot, not a full stop, e.g. m·s^-1. For marking purposes, m.s^-1 and m/s will also be accepted.
   5.4 Positive marking
   Positive marking regarding calculations will be followed in the following cases:
   5.4.1 Subquestion to subquestion: When a certain variable is incorrectly calculated in one
   subquestion (e.g. 3.1) and needs to be substituted into another subquestion (3.2 or 3.3),
   full marks are to be awarded for the subsequent subquestions.
   5.4.2 A multistep question in a subquestion: If the candidate has to calculate, for example,
   current in the first step and gets it wrong due to a substitution error, the mark for the
   substitution and the final answer will be forfeited.
   5.5 Negative marking
   Normally an incorrect answer cannot be correctly motivated if based on a conceptual mistake. If
   the candidate is therefore required to motivate in QUESTION 3.2 the answer given to
   QUESTION 3.1, and QUESTION 3.1 is incorrect, no marks can be awarded for QUESTION 3.2.
   However, if the answer for, for example, QUESTION 3.1 is based on a calculation, the motivation
   for the incorrect answer in QUESTION 3.2 should be considered.

6. MARKING GUIDELINES: PAPER 2
   6.1 Calculations
   6.1.1 Marks will be awarded for: correct formula, correct substitution, correct answer with unit.
   6.1.2 No marks will be awarded if an incorrect or inappropriate formula is used, even though there may be relevant symbols and applicable substitutions.
   6.1.3 When an error is made during substitution into a correct formula, a mark will be awarded for the correct formula and for the correct substitutions, but no further marks will be given.
   6.1.4 If no formula is given, but all substitutions are correct, the candidate will forfeit one mark.
   Example: No Kc expression, correct substitution:
   K_c =   (2)² = 2        (2)
           (2)(1)               3
   6.1.5 Marks are only awarded for a formula if a calculation has been attempted, i.e. substitutions have been made or a numerical answer has been given.
   6.1.6 Marks can only be allocated for substitutions when values are substituted into formulae and not when listed before a calculation starts.
   6.1.7 The final answer to all calculations, when not specified in the question, must be rounded off to a minimum of TWO decimal places.
   6.1.8 If a final answer to a calculation is correct, full marks will not automatically be awarded. Markers will always ensure that the correct/appropriate formula is used and that workings, including substitutions, are correct.
   6.1.9 Mathematical manipulations and change of subject of appropriate formulae carry no marks, but if a candidate starts off with the correct formula and then changes the subject of the formula incorrectly, marks will be awarded for the formula and the correct substitutions. The mark for the incorrect numerical answer is forfeited.
   Example:

   CORRECT	ANSWER (1)	POSSIBLE	ANSWER (2)	POSSIBLE
   n= m       M 0,01 = m            52 m = 0,52g (4)	n = m       M 0,01 = 52              m m = 5200g (2)	n = m       M = 0,01      52 = 0,002 g (0)	n= m      M m = M         n =  52     0,001 = 5200g (3)	n= m      M = 0,52g (2)

   6.2 Units
   6.2.1 Candidates will only be penalised once for the repeated use of an incorrect unit within a question.
   6.2.2 Units are only required in the final answer to a calculation.
   6.2.3 Marks are only awarded for an answer and not for a unit per se. Candidates will therefore forfeit the mark allocated for the answer in each of the following situations:

   • Correct answer + wrong unit
   • Wrong answer + correct unit
   • Correct answer + no unit
     6.2.4 Separate compound units with a multiplication dot, not a full stop, e.g. mol·dm^-3.
     Accept mol.dm^-3 (or mol/dm3) for marking purposes.
     6.3 General
     6.3.1 If one answer or calculation is required, but two are given by the candidate, only the first one will be marked, irrespective of which one is correct. If two answers are required, only the first two will be marked, etc.
     6.3.2 When a chemical FORMULA is asked, and the NAME is given as answer, the candidate forfeits the marks. The same rule applies when the NAME is asked and the FORMULA is given.
     6.3.3 When redox half-reactions are to be written, the correct arrow should be used. If the equation
     H₂S → S + 2H⁺ + 2e^- (2)
                                         2
     is the correct answer, the marks must be given as follows:
     H₂S  S + 2H⁺ + 2e^- (1)
                                      2
     H₂S ← S + 2H⁺ + 2e^- (0)
                                         2
     S + 2H⁺ + 2e^- ← H₂S (2)
                                         2
     S + 2H⁺ + 2e^- ← H₂S (0)
                                         2
     6.3.4 When candidates are required to give an explanation involving the relative strength of oxidising and reducing agents, do not accept the following:
   • Stating the position of a substance on Table 4 only (e.g. Cu is above Mg).
   • Using relative reactivity only (e.g. Mg is more reactive than Cu).
   • The correct answer would be for instance: Mg is a stronger reducing agent than Cu, and therefore Mg will be able to reduce Cu2+ ions to Cu. The answer can also be given in terms of the relative strength as electron acceptors and donors.
     6.3.5 One mark is forfeited when the charge of an ion is omitted per equation (not for the charge on an electron).
     6.3.6 The error-carrying principle does not apply to chemical equations or half-reactions. For example, if a learner writes the wrong oxidation/reduction half-reaction in the subquestion and carries the answer to another subquestion (balancing of equations or calculation of (E^θ_cell), then the learner will not be credited for this substitution.
     6.3.7 In the structural formula of an organic molecule all hydrogen atoms must be shown. Marks must be deducted if hydrogen atoms are omitted.
     6.3.8 When a structural formula is required, marks must be deducted if the candidate writes the condensed formula.
     6.3.9 When a IUPAC name is asked and the candidate omits the hyphen (e.g. instead of pent-1-ene or 1-pentene the candidate writes pent 1 ene or 1 pentene), marks will be forfeited.
     6.3.10 When a chemical reaction is asked, marks are awarded for correct reactants, correct products and correct balancing.
     If only a reactant(s) followed by an arrow, or only a product(s) preceded by an arrow, is/are written, marks may be awarded for the reactant(s) or product(s). If only a reactant(s) or only a product(s) is/are written, without an arrow, no marks are awarded for the reactant(s) or product(s).
     Examples:
     N₂ + 3H₂ → 2NH₃ bal 3
                                           3
     N₂ + H₂ → 1
                       3
     → NH₃    1 
                    3
     N₂ + H₂    0
                      3
     NH₃   0
               3
     6.4 Positive marking
     Positive marking regarding calculations will be followed in the following cases:
     6.4.1 Subquestion to subquestion: When a certain variable is calculated in one subquestion (e.g. QUESTION 3.1) and needs to be substituted in another (QUESTION 3.2 or QUESTION 3.3), e.g. if the answer for QUESTION 3.1 is incorrect and is substituted correctly in QUESTION 3.2 or QUESTION 3.3, full marks are to be awarded for the subsequent subquestions.
     6.4.2 A multistep question in a subquestion: If the candidate has to calculate, for example, current in the first step and gets it wrong due to a substitution error, the mark for the substitution and the final answer will be forfeited.
     6.5 Negative marking
     Normally an incorrect answer cannot be correctly motivated if based on a conceptual mistake. If the candidate is therefore required to motivate in QUESTION 3.2 the answer given to QUESTION 3.1, and QUESTION 3.1 is incorrect, no marks can be awarded for QUESTION 3.2.
     However, if the answer for e.g. QUESTION 3.1 is based on a calculation, the motivation for the incorrect answer in QUESTION 3.2 could be considered.
7. CONCLUSION
   This Examination Guidelines document is meant to articulate the assessment aspirations espoused in the CAPS document. It is therefore not a substitute for the CAPS document which teachers should teach to.
   Qualitative curriculum coverage as enunciated in the CAPS cannot be