Double Award Science - Chemistry - Unit 7 Practical Skills - Booklet B - Higher Tier - Paper

Sep 5, 2026

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GCSE Double Award Science (Higher Tier) Chemistry Unit 7 Practical Skills Booklet B question paper assesses practical understanding through three chemistry tasks. Students investigate rusting under different conditions, explain oxidation in the context of rusting, and identify protective measures using magnesium. The chromatography task evaluates understanding of stationary phase, solvent front, dye identification, solubility, and calculation of Rf values. A final kinetics question uses magnesium reacting with hydrochloric acid at varying concentrations, requiring graphing rates, interpolation, and fair test variables.

LanguageEnglish

CategoryExam

FormatPDF

Pages14

Reading Time35 min

AccessFree to download

1 Rusting investigation

(a) Rusting experiment setup and explanations

(b) Oxidation and magnesium protection

2 Paper chromatography of dyes

(a) Stationary phase, solvent front, dye identification

(b) Solubility and experimental method with Rf calculation

3 Concentration and rate of reaction

(a) Plotting rate vs concentration and trend

(b) Reading rate, calculating time, and fair test factors

| |

General Certificate of Secondary Education 2023 | |
Centre Number

Candidate Number
| | --- | --- | --- | --- | | Double Award Science: Chemistry
Unit 7 Practical Skills
Booklet B
Higher Tier
[GDW77]
TUESDAY 13 JUNE, MORNING * GDW77*
* GDW77*

TIME
30 minutes.

INSTRUCTIONS TO CANDIDATES
Write your Centre Number and Candidate Number in the spaces provided at the top of this page.
You must answer the questions in the spaces provided.
Do not write outside the boxed area on each page or on blank pages.
Complete in black ink only. Do not write with a gel pen.
Answer all three questions.

INFORMATION FOR CANDIDATES
The total mark for this paper is 35.
Figures in brackets printed down the right-hand side of pages indicate the marks awarded to each question or part question.
A Data Leaflet including a Periodic Table of the Elements is provided. Quality of written communication will be assessed in Question 2(b) . | | | | | 13916 | | | | *12GDW7701* *12GDW7701* | |
1 (a) The process of rusting can be investigated experimentally. The following experiment was set up by placing iron nails in test tubes under different conditions. | | --- | --- | | water

Test tube A

oil
boiled water

cotton wool

anhydrous calcium chloride
Test tube C

(i) The test tubes were left for a week. In which test tube (A, B or C) did the nail rust? Explain your answer.
Test tube Explanation [2]
(ii) Suggest why the layer of oil is present in test tube B. | | | [1](iii) What is the purpose of the anhydrous calcium chloride in test tube C?
[1]
13916 | | *12GDW7702* *12GDW7702* (b) Explain why rusting is an example of an oxidation reaction. [2] (c) A piece of magnesium ribbon is wrapped around an iron nail. The nail is placed in water but it does not rust. The magnesium protects the iron from rusting. (i) Explain why the iron does not rust. [2](ii) What is the name of this type of protection from rusting? [1] 13916 [Turn over *12GDW7703* *12GDW7703* | |
2 The results of a paper chromatography experiment involving a mixture of dyes (labelled M) and four pure dyes (labelled D1, D2, D3 and D4) are shown below. | | | | --- | --- | --- | --- | | base line | | | | | M D1 D2 D3 D4
(a) (i) What is the stationary phase in paper chromatography?
[1]
(ii) Label the solvent front on the chromatogram above. [1]
(iii) Identify which pure dyes are present in the mixture of dyes, M. [1] | | | | | 13916 | | | | *12GDW7704* *12GDW7704* (iv) Which one of the pure dyes (D1, D2, D3 or D4) is the least soluble in the solvent? Give a reason for your answer. Dye: Reason: [2] 13916 [Turn over *12GDW7705* *12GDW7705* | |
(b) Describe how a student can carry out an experiment to achieve the results shown in the chromatogram and how they would use it to calculate Rf values.
In your answer you should describe: | | | --- | --- | --- | | 􀁹 how to prepare the chromatography paper
􀁹 how the chromatography experiment is carried out
􀁹 when the experiment should be stopped and how this is achieved
􀁹 how Rf values are calculated.
In your answer you will be assessed on the quality of written communication including the use of specialist scientific terms.
How to prepare the chromatography paper:
How the chromatography experiment is carried out:
| | | | 13916 | | | *12GDW7706* *12GDW7706* | |
When the experiment should be stopped and how this is achieved: | | | --- | --- | --- | | How Rf values are calculated:

[6] | | | | 13916 | | [Turn over

| *12GDW7707* *12GDW7707* | |
3 A series of experiments was carried out to investigate the effect of concentration on the rate of reaction. A strip of magnesium ribbon was reacted with five different concentrations of hydrochlor

FAQs

What are the three main questions in this Chemistry Practical Skills paper?

The paper includes: (1) investigating rusting under different conditions and explaining oxidation, (2) analyzing paper chromatography results and calculating Rf values, and (3) studying how acid concentration affects the rate of reaction and using a graph to find rates and times.

How does the chromatography question assess Rf values?

Students must describe how to carry out the chromatography experiment and then calculate Rf values from the chromatogram using the measured distances for the dye spots and the solvent front.

What is required in the reaction rate question about magnesium and hydrochloric acid?

Students must plot a graph of rate versus acid concentration with a line of best fit, use the graph to determine the rate at a given concentration, calculate the time for magnesium to disappear, and state factors to keep the test fair.

Sep 5, 2026

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