MARKS: 150 

TIME: 3 hours 

INSTRUCTIONS AND INFORMATION 

1. Write your name and surname in the appropriate space on the ANSWER  BOOK. 

2. This question paper consists of SEVEN questions. Answer ALL the questions  in the ANSWER BOOK. 

3. Start EACH question on a NEW page in the ANSWER BOOK. 

4. Number the answers correctly according to the numbering system used in this  question paper. 

5. Leave ONE line between two sub-questions, for example between  QUESTION 2.1 and QUESTION 2.2. 

6. You may use a non-programmable calculator. 

7. You may use appropriate mathematical instruments. 

8. Show ALL formulae and substitutions in ALL calculations. 

9. Round off your FINAL numerical answers to a minimum of TWO decimal  places. 

10. Give brief motivations, discussions, et cetera. where required. 11. You are advised to use the attached DATA SHEETS. 

12. Write neatly and legibly.

QUESTION 1: MULTIPLE-CHOICE QUESTIONS 

Various options are provided as possible answers to the following questions. Choose the answer and write only the letter (A–D) next to the question numbers (1.1 to 1.10)  in the ANSWER BOOK, for example 1.11 E. 

1.1 The homologous series that contain a carbon-carbon triple bond is …

A alkanes. 
B alkenes. 
C alkynes. 
D haloalkanes. (2)

1.2 Consider the following compounds: 

Compounds 

Which ONE of the following correctly rank the above pure substances in the  order of increasing strength of intermolecular forces? 

A Pentan-1-ol, butan-1-ol, pentanoic acid 
B Pentanoic acid, butan-1-ol, pentan-1-ol 
C Butan-1-ol, pentanoic acid, pentan-1-ol 
D Butan-1-ol, pentan-1-ol, pentanoic acid (2)

1.3 Consider the structural formula:  

Which ONE of the following compounds contains the above functional group?

A Propanal 
B Propanone 
C Propan-1-ol 
D Propanoic acid (2)

1.4 2-methylpropan-1-ol can form two isomers. Which ONE of the following  combinations CORRECTLY identifies the ISOMER and the TYPE OF  ISOMER? 

1.5 The conversion of CH3CHCH2 to CH3CH2CH3 is known as …

A hydration. 
B hydrogenation. 
C halogenation. 
D hydrohalogenation. (2) 

1.6 Hydrochloric acid reacts with EXCESS zinc according to the balanced  equation: 

2 HCℓ (aq) + Zn (s) → ZnCℓ₂ (aq) + H₂ (g) 

Which ONE of the following factors will influence the yield of H₂ (g) but not  on the rate of production of H2 (g)? 

A Temperature 
B Volume of HCℓ 
C State of division of Zn 
D Concentration of HCℓ (2)

1.7 Carbonic acid, H2CO3, ionises in water in two steps. The first step of the  ionisation is given by the equation: 

H₂CO₃ (aq) + H₂O (ℓ) ⇌ HCO₃ ^- (aq) + H₂O⁺(aq) 

Which ONE of the following substances in the above reaction can act as an  ampholyte? 

A H₂CO₃ and H₂O
B HCO₃ ^- and H₃O⁺
C H₂O and HCO₃ ^-  
D H₂CO₃ and HCO₃ ^- (2) 

1.8 The potential energy diagram for the following reversible hypothetical  reaction is given: 

2 AB (g) ⇌ A₂ (g) + Br₂ (g) 

Consider the following statements regarding the energy diagram.

I Δ H for the forward reaction is positive 

II Catalyst would lower P–Q 

III Reversible reaction is exothermic 

Which of the statement(s) above is/are TRUE? 

A I only 
B I and II only 
C I and III only 
D II and III only (2) 

1.9 Consider the following reversible reaction at equilibrium in a sealed  container: 

C (s) + CO₂ (g) ⇌ 2 CO (g) 

The volume inside the container is decreased while the temperature remains  constant. 

Which ONE of the following combinations are CORRECT regarding the  amount of CO and the rate at which the new equilibrium is reached? 

(2) 

1.10 Consider two solutions of Ba(OH)₂ (aq) and KOH (aq) each with a  concentration of 0,1 mol·dm-3. 

Consider the following statements regarding the two solutions. 

I Both KOH and Ba(OH)₂ can be regarded as Arrhenius bases 

II Ba(OH)₂ will produce a higher concentration of OH–than KOH when  it dissociates 

III Double the amount of HCℓ is needed to neutralise KOH than Ba(OH)₂

Which of the statement(s) above is/are TRUE? 

A I only 
B I and II only 
C II and III only 
D I and III only (2) [20]

QUESTION 2 (Start on a new page.) 

The table below shows organic molecules A to E from different homologous series. 

2.1 Define homologous series. (2)

2.2 Write down the LETTER that represents the following compounds:

2.2.1 Hydrocarbon (1)

2.2.2 Haloalkane (1)

2.2.3 Alkene (1) 

2.2.4 The compound that contains the carbonyl group that is bonded to two  saturated carbon atoms (1) 

2.3 Is compound D a PRIMARY, SECONDARY OR TERTIARY ALCOHOL? Give a reason for the answer. (2) 

2.4 Write down the: 

2.4.1 General formula for the homologous series to which compound B belong. (1) 

2.4.2 IUPAC name of compound B (2)

2.4.3 IUPAC name of compound D (3)

2.5 Compound C has a functional isomer. 

2.5.1 Define the term functional isomer. (2) 

2.5.2 Draw the STRUCTURAL FORMULA of the functional isomer of  compound C. (2)

2.6 Compound E (C_XH_YO₂) reacts with alcohol P in the presence of concentrated  sulphuric acid (H₂SO₄) to produce organic compound Q as shown by the  incomplete equation below: 

C_XH_YO₂ + alcohol P → organic compound Q + H₂O 

The percentage composition of compound Q is: 

The molecular mass of the compound Q is EQUAL to the formula mass.

2.6.1 Write down the name of the type of reaction that occurred. (1) 

2.6.2 Determine, by calculation, the molecular formula of organic  compound Q. (5) 

Compound E (C_XH_YO₂) has a molecular mass of 74 g·mol-1. 

2.6.3 Determine the compound E (C_XH_YO₂) and write down its IUPAC  name. (4) 

2.6.4 Determine the organic compound Q that was produced, write down  its IUPAC name and STRUCTURAL FORMULA. (6) [34]

QUESTION 3 (Start on a new page.) 

An investigation is carried out to determine the effect of branching on the boiling points  of an organic compounds. Three PRIMARY ALCOHOLS that each contains 5 carbon  atoms are used during this investigation. 

Equal volumes of each alcohol are heated separately in a water bath. 

3.1 Define boiling point. (2)

3.2 What property of alcohols requires them to be heated in a water bath? (1)

3.3 Write down the boiling point of alcohol 1. (1) 

3.4 Is this a fair investigation? Write only YES or NO.Give a reason for the answer. (2)

3.5 Give the IUPAC name of alcohol 2. (2)

3.6 Which alcohol has the shortest chain length? Write down only ALCOHOL 1, ALCOHOL 2 or ALCOHOL 3. (1)

3.7 Fully explain the answer to QUESTION 3.6. (3) 

3.8 A second investigation is carried out to determine the effect of intermolecular  forces on the vapour pressure.  

The table below summarises the results from two organic compounds. 

3.8.1 Define vapour pressure. (2) 

3.8.2 Explain the difference in vapour pressures by referring to the  intermolecular forces involved. (4) 

3.8.3 Will the vapour pressure of the above compounds INCREASE,  DECREASE or REMAIN THE SAME at a higher temperature? (1) [19]

QUESTION 4 (Start on a new page.) 

4.1 Consider the flow diagram showing organic reactions given below.  Reaction 1 

Consider REACTION 1.

Write down the: 

4.1.1 Name of the type of elimination reaction (1)

4.1.2 Name or formula of the inorganic reagent needed (1) 

4.1.3 Balanced equation using STRUCTURAL FORMULAE for the organic  compounds (4) 

Consider REACTION 2. 

Write down the: 

4.1.4 Name the type of reaction taking place (1) 

4.1.5 STRUCTURAL FORMULA and IUPAC name for the major product  formed (4) 

Consider REACTION 3. 

Write down the: 

4.1.6 TWO reaction conditions needed (2) 

4.2 Octane can be cracked according to the incomplete equation:

C₈H₁₈ → C₄ H_Y + C₄ H_Z

The two STRAIGHT CHAIN organic compounds, C₄ H_Z and C₄ H_Y, are now passed through bromine water (Br₂ (aq)) at room temperature in a darken room. The  following observations are made: 

4.2.1 Define cracking. (2)

4.2.2 Give a reason why experiments 1 and 2 is carried out in a darken room. (1) 

4.2.3 Which compound, C₄ H_Y or C₄ H_Z, is UNSATURATED? Give a reason for the answer. 

Compound C₄ H_Y undergoes the following reactions: 

Write down the: 

4.2.4 STRUCTURAL FORMULA for compound C₄ H_Z (2) 

4.2.5 Combustion reaction of compound C₄ H_Y using MOLECULAR  FORMULAE (3) [23] 

QUESTION 5 (Start on a new page.) 

A group of learners use the reaction between magnesium carbonate (MgCO₃) and  EXCESS hydrochloric acid (HCℓ) to investigate some of the factors that affect the reaction rate. The balanced equation for the reaction is: 

MgCO₃ (aq) + 2 HCℓ (aq) MgCℓ₂ (aq) + H₂ O (ℓ) + CO₂ (g) 

The learners used the apparatus illustrated below. 

The table below summarises the reaction conditions: 

5.1 Define reaction rate. (2) 

5.2 Write down the independent variable for the comparison between  experiment 1 and 2. (1) 

5.3 Experiment 2 and 3 is now compared. 

5.3.1 Which experiment, 2 or 3, will have the highest reaction rate? (1) 

5.3.2 Explain the answer to QUESTION 5.3.1 by referring to the collision  theory. (3) 

5.4 The learners measured the rate at which CO₃ was produced in experiment 2  and found it to be 0,25 g·min^-1. It took 10,44 minutes to measure the time taken  for the reaction to reach completion. 

Calculate the: 

5.4.1 Mass of MgCO₃ that was used (6)

5.4.2 Molar volume of CO₂ if 1,47 dm³ of CO₂ was released (3) 

5.5 The graph below represents Maxwell-Boltzmann distribution curve for CO2(g)  produced experiment 1. 

Redraw the graph in your ANSWER BOOK. Clearly label the curve as A. 

On the same set of axes, sketch the curve that will be obtained for CO₂(g) if  the mass of MgCO₃ used is increased. Label this curve as B. (2) [18] 

QUESTION 6 (Start on a new page.) 

6.1 Initially 1 mol of sulphur dioxide SO₂ (g) and oxygen O₂ (g) are allowed to react  in a sealed container according to the balanced equation: 

2 SO₂(g) + O₂(g) ⇌ 2 SO₃ (g) 

The graph below shows the change in amounts of reactants and products  over time. 

Graph is NOT drawn to scale. 

6.1.1 State Le Chatelier’s principle in words. (2) 

6.1.2 How will the rate of the forward reaction compare to the rate of the  reverse reaction between t₁ and t₂? 

Choose from HIGHER THAN, LOWER THAN or EQUAL TO. 
Give a reason for the answer. (2)

6.1.3 Which curve, X or Y, represent SO₂? 

Give a reason for the answer. (2) 
The temperature of the reaction mixture was decreased at t₂. 

6.1.4 Is the heat of the reaction (ΔH) POSITIVE or NEGATIVE for the  forward reaction? (1) 

6.1.5 Explain the answer to QUESTION 6.1.4 by referring to Le Chatelier’s  principle. (3) 

6.2 2,5 mol of NOCℓ was initially placed in a 1,5 dm3 sealed container at 400 °C.  After the equilibrium was established, it was found that 28% of the NOCℓ  dissociated according to the balanced equation: 

2 NOCℓ (g) ⇌ 2 NO (g) + Cℓ₂ (g) 

6.2.1 Calculate the equilibrium constant, Kc-value at 400 °C. (7) 

6.2.2 More NOCℓ is added to the equilibrium mixture. How will this change  affect the equilibrium constant, Kc? 

Write down only INCREASES, DECREASES or REMAINS THE  SAME. 
Give a reason for your answer. (2) [19]

QUESTION 7 (Start on a new page.) 

7.1 The balanced equation below represents the first step of the ionisation reaction  of sulphuric acid (H₂ SO₄): 

H₂ SO (aq) + H₂ O(ℓ) ⇌ HSO₄ ^-(aq) + H₃ O+(aq) 

7.1.1 Define an acid according to the Arrhenius theory. (2)
Write down the: 

7.1.2 FORMULAE of the TWO BASES in the above reaction (2) 

7.1.3 Balanced chemical equation for the reaction between sulphuric acid  (H₂ SO₄) and potassium hydroxide (KOH) (3) 

7.2 A standard solution of sodium hydroxide (NaOH) is prepared by dissolving  3,812 g to make a 100 cm³ NaOH solution. 

7.2.1 Calculate the concentration of sodium hydroxide (NaOH) solution. (3) 

Household vinegar contains x % ethanoic acid (CH₃COOH) by mass. 25 cm³ of  vinegar reacts with 21,8 cm³ sodium hydroxide (NaOH) solution prepared in  QUESTION 7.2.1. 

The balanced equation is: 

CH₃COOH (aq) + NaOH (aq) → CH₃COONa (aq) + H₂O(ℓ) 

7.2.2 Calculate the percentage mass of the ethanoic acid (value of x) found in  the vinegar if 1 cm3 of household vinegar has a mass of 1 g. (7) [17] 

TOTAL: 150

DATA FOR PHYSICAL SCIENCES GRADE 12 

PAPER 2 (CHEMISTRY) 

TABLE 1: PHYSICAL CONSTANTS/TABEL 1: FISIESE KONSTANTES 

TABLE 2: FORMULAE/TABEL 2: FORMULES

TABLE 3: THE PERIODIC TABLE OF ELEMENTS/TABEL 3: DIE PERIODIEKE TABEL VAN ELEMENTE