AQA GCSE Combined Science Chemistry Higher - November 2021 Paper 2H - Exam questions

Sep 5, 2026

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Higher Tier GCSE Combined Science Chemistry Paper 2H focuses on practical and conceptual chemistry. Questions include planning investigations on reaction rate using magnesium and hydrochloric acid, identifying independent and control variables, plotting and interpreting gas volume data, and explaining how temperature and particle collisions affect reaction rate. Further items cover crude oil and alkane formation, comparing methane and hexane properties, cracking hydrocarbons, testing for alkenes, and using copper sulfate as a water test alongside the meaning of a pure substance.

LanguageEnglish

CategoryExam

FormatPDF

Pages28

Reading Time1 h 11 min

AccessFree to download

Question 1: Magnesium + hydrochloric acid investigation

Independent and control variables

Plotting data and line of best fit

Rate change over time and concentration effect

Effect of temperature (particles and collisions)

Question 2: Crude oil, alkanes and properties

Decomposition producing crude oil

Identify an alkane with three carbon atoms

Compare methane and hexane

Cracking decane equation

Test for alkenes

Question 3: Potable water testing

Copper sulfate test for water

Definition of a pure substance

| Please write clearly in block capitals. | | | | | --- | --- | --- | --- | | Centre number | | Candidate number | | | Surname
Forename(s)
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I declare this is my own work. | | | | GCSE COMBINED SCIENCE: TRILOGY Higher Tier Chemistry Paper 2H H Time allowed: 1 hour 15 minutes Materials For this paper you must have: • a ruler • a scientific calculator • the periodic table (enclosed) . Instructions • Use black ink or black ball-point pen. • Pencil should only be used for drawing. • Fill in the boxes at the top of this page. • Answer all questions in the spaces provided. • If you need extra space for your answer(s), use the lined pages at the end of this book. Write the question number against your answer(s) . • Do all rough work in this book. Cross through any work you do not want to be marked. • In all calculations, show clearly how you work out your answer. | For Examiner’s Use | | | --- | --- | | Question | Mark | | 1 | | | 2 | | | 3 | | | 4 | | | 5 | | | 6 | | | TOTAL | | Information • The maximum mark for this paper is 70. • The marks for questions are shown in brackets. • You are expected to use a calculator where appropriate. • You are reminded of the need for good English and clear presentation in your answers. *jun218464c2h01* IB/M/Jun21/E7 8464/C/2H 2 There are no questions printed on this page DO NOT WRITE ON THIS PAGE ANSWER IN THE SPACES PROVIDED *02* IB/M/Jun21/8464/C/2H Do not write outside the box 3 0 1 A student investigated the reaction between magnesium and excess hydrochloric acid. Figure 1 shows the apparatus. Figure 1 This is the method used. 1. Pour 50 cm3 of hydrochloric acid into a conical flask. 2. Add a piece of magnesium. 3. Insert stopper and delivery tube and start a timer. 4. Collect the gas produced in a gas syringe. 5. Record the volume of gas produced every 20 seconds for 2 minutes. 6. Repeat steps 1 to 5 with higher concentrations of hydrochloric acid. 0 1 . 1 Give the independent variable and one control variable in this investigation. [2 marks] Independent variable Control variable Question 1 continues on the next page *03* Turn over ► IB/M/Jun21/8464/C/2H 4 Table 1 shows the results from the first experiment using hydrochloric acid with a low concentration. Table 1 | Time in seconds | 0 | 20 | 40 | 60 | 80 | 100 | 120 | | --- | --- | --- | --- | --- | --- | --- | --- | | Volume of gas in cm3 | 0 | 48 | 72 | 90 | 97 | 98 | 98 | 0 1 . 2 Complete Figure 2. You should: • plot the data from Table 1 (the point 0,0 has been plotted for you) • draw a line of best fit. [3 marks] Figure 2 *04* IB/M/Jun21/8464/C/2H Do not write outside the box 5 | 0 | 1 | . | 3 | | --- | --- | --- | --- | How does the rate of this reaction change with time? Use Table 1. [1 mark] Tick (􀀹) one box. The rate decreases. The rate stays the same. The rate increases. The student repeated the experiment using hydrochloric acid with a higher concentration. Which statement is correct? [1 mark] Tick (􀀹) one box. The activation energy for the reaction was higher. The magnesium reacted more quickly. The reaction finished at the same time. The total volume of gas collected was smaller. | 0 | 1 | . | 4 | | --- | --- | --- | --- | Question 1 continues on the next page *05* Turn over ► IB/M/Jun21/8464/C/2H Do not write outside the box 6 | | | | | | Temperature also affects the rate of the reaction. | Do not
outside box | | --- | --- | --- | --- | --- | --- | --- | | | 0 | 1 | . | 5 | | | | Explain how increasing the temperature affects the rate of the reaction.
You should refer to particles and collisions.
[3 marks]
| | | | | | | | | | | | | | | | | | | | | | 10 | | | | | | | | | write the *06* IB/M/Jun21/8464/C/2H 7 | 0 2
0 2
0 2 | Crude oil

FAQs

What are the independent variable and one control variable in the magnesium and hydrochloric acid investigation?

The independent variable is the concentration of hydrochloric acid. One control variable is to keep the magnesium amount the same (for example, use the same piece/mass of magnesium).

How do temperature changes affect the rate of the reaction?

Increasing temperature increases the rate by increasing particle collisions, leading to more particles with enough energy to react.

How can copper sulfate be used to test for the presence of water?

Copper sulfate can be used as a water test based on the change it undergoes when water is present, indicating the presence of water in the sample.

Sep 5, 2026

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