Grade 10 Physical Sciences · Paper 2 (Chemistry)

Chemical Change Grade 10

Real past paper questions and answers from 2023 to 2025, with each memo split into the ticks examiners give. Try one, mark yourself, and see exactly which skill cost you marks.

past paper questions: 79 past paper questions
skills: 13 skills
videos: 13 videos

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Question 4.5 · May/June 2025 · Paper 2 · National (DBE) · 3 marks

In the flow diagram below, a primary alcohol P is used as a starting reactant to form different organic compounds under different reaction conditions. Diagram for this question

4.5 Write down a balanced equation using MOLECULAR FORMULAE for the complete combustion of butane.(3)

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What's in Chemical Change Grade 10

Each skill is one thing a memo gives a tick for. Tap a skill for its own questions, notes and videos.

Physical and Chemical Change15 past paper questions

Representing Chemical Change33 past paper questions

Reactions in Aqueous Solution3 past paper questions

Stoichiometry48 past paper questions

More Chemical Change Grade 10 questions and answers

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1. Question 7.1 · November 2024 · Paper 2 · Provincial · 4 marks
7.1 Calculate the concentration of a solution prepared by dissolving $5, 85$ g of sodium chloride in enough water to make a $500$ cm $^{3}$ solution.(4)
Show the memo (4 ticks)Memo
1. ✓
  OPTION 1: Moles of NaCl $n (NaC ℓ) = \frac{m}{M} = \frac{5 , 85}{58 , 5}$
  $= 0, 1$ mol
  1 mark · Calculate number of moles
2. ✓
  OPTION 1: Formula $c (NaC ℓ) = \frac{n}{V}$
  1 mark · Calculate concentration of a solution
3. ✓
  OPTION 1: Substitution $= \frac{0 , 1}{0 , 5}$
  1 mark · Calculate concentration of a solution
4. ✓
  OPTION 1: Answer with unit $= 0, 2$ mol·dm $^{- 3}$
  1 mark · Calculate concentration of a solution
2. Question 4.1.3 · November 2023 · Paper 2 · National (DBE) · 3 marks
4.1 Consider the cracking reaction below.

$C_{16} H_{34} \to C_{6} H_{14} + C_{6} H_{x} + 2 C_{y} H_{z}$
Compound $C_{6} H_{14}$ undergoes complete combustion.
4.1.3 Using MOLECULAR FORMULAE, write down the balanced equation for this reaction.(3)
Show the memo (3 ticks)Memo
1. ✓
  Reactant: $O_{2}$ $2 C_{6} H_{14} + 19 O_{2}$
  1 mark · Write a chemical equation
2. ✓
  Products $\to 12 CO_{2} + 14 H_{2} O$
  1 mark · Write a chemical equation
3. ✓
  Balancing $2 C_{6} H_{14} + 19 O_{2} \to 12 CO_{2} + 14 H_{2} O$
  1 mark · Balance a chemical equation
3. Question 8.1.3 · November 2024 · Paper 2 · Provincial · 1 mark
8.1 A solution of nickel (II) nitrate is placed in a zinc container. It was observed, after some time, that a chemical reaction has taken place. The net ionic equation is:

$Zn(s) + Ni^{2 +} (aq) ⇌ Zn^{2 +} (aq) + Ni(s)$
8.1.3 Give a reason why the nitrate ion ( $NO_{3}^{-}$ ) is not written in the net ionic equation above.(1)
Show the memo (1 tick)Memo
1. ✓
  Spectator ionNitrate ion ( $NO_{3}^{-}$ ) is a spectator ion / undergoes no changes in its oxidation state.
  1 mark · Describe ions and reactions in solution
4. Question 1.6 · November 2023 · Paper 2 · Provincial · 2 marks
Four options are provided as possible answers to the following questions. Each question has only ONE correct answer. Choose the answer and write only the letter (A–D) next to the question numbers (1.1 to 1.9) in the ANSWER BOOK, e.g. 1.10 D.
1.6 Which of the following equations represents a chemical change?(2)
1. A $H_{2} O(s) \to H_{2} O (ℓ)$
2. B $2 H_{2} O (ℓ) \to 2 H_{2} (g) + O_{2} (g)$
3. C $NaC ℓ (s) \to Na^{+} (aq) + C ℓ^{-} (aq)$
4. D $CO_{2} (s) \to CO_{2} (g)$
Show the memo (1 tick)Memo
1. ✓
  Correct optionIn a chemical change new substances form: water is decomposed into hydrogen and oxygen, so bonds inside the molecules break. A and D are phase changes (the same substance in another state) and C is dissolving, which are physical changes.
  
  Answer: B
  2 marks · Describe physical and chemical change
5. Question 1.4 · November 2024 · Paper 2 · Provincial · 2 marks
1.4 The molar mass of hydrated oxalic acid $(COOH)_{2} \cdot x H_{2} O$ is $126$ g·mol $^{- 1}$ .

The number of water molecules ( $x$ ) present in the hydrated compound is ...(2)
1. A 1.
2. B 2.
3. C 3.
4. D 4.
Show the memo (1 tick)Memo
1. ✓
  Work back from the molar mass to x $M ((COOH)_{2}) = 2 (12 + 16 + 16 + 1) = 90$ g·mol $^{- 1}$
  Mass of water: $126 - 90 = 36$ g·mol $^{- 1}$
  $x = \frac{36}{18} = 2$
  
  Answer: B
  2 marks · Calculate molar mass

Chemical Change Grade 10 videos

Short lessons from South African teachers first. Videos load only when you tap play, to save your data.

Grade 10 Chemistry Physical and Chemical changeMiss Martins Maths and Science

Conservation Of Mass Grade 10Kevinmathscience

The mole concept: What is a mole? Quantitative aspects of chemical changeMiss Martins Maths and Science

4) Naming metal and non metal Gr 10Kevinmathscience

Writing Ionic Formulas: IntroductionTyler DeWitt

Balancing Reactions Grade 10Kevinmathscience

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