0653.C7.1.02 — Describe acids in terms of their effect on the indicators: (a).litmus (b). methyl orange: past paper questions
Real questions on 0653.c7.1.02 — describe acids in terms of their effect on the indicators: (a).litmus (b). methyl orange
The newest 11 of 11 written questions. Open one to see it on the real paper.
- 0653/42 · October/November 2025 · Q4a(ii)[2]
State the colour change of the methyl orange indicator during this reaction. from to
See it on the paper → - 0653/42 · May/June 2025 · Q5b(ii)[1]
Aqueous calcium hydroxide is an alkali. State the colour of methyl orange indicator in aqueous calcium hydroxide.
See it on the paper → - 0653/61 · May/June 2025 · Q3b(ii)[2]
Identify what type of substance is aqueous H. Explain your answer using information from Table 3.2. explanation type of substance
See it on the paper → - 0653/62 · February/March 2025 · Q2c[1]
Explain why it is difficult to see the actual colour of the universal indicator in aqueous H.
See it on the paper → - 0653/62 · February/March 2025 · Q2d[1]
Acids have a pH that is less than 7. State which one of the aqueous solutions is an acid, H, J, K or L.
See it on the paper → - 0653/62 · February/March 2025 · Q2e[1]
Determine which solution, H, J, K or L, is a carbonate. Explain your answer. solution explanation
See it on the paper → - 0653/62 · February/March 2025 · Q3[7]
When a detergent is shaken with water it forms a layer of bubbles called foam. Plan an investigation to determine the relationship between the temperature of water and the amount of foam produced when detergent is shaken with water. You are provided with the apparatus shown in Fig. 3.1. stopper measuring cylinder Fig....
See it on the paper → - 0653/63 · October/November 2023 · Q3a(ii)[1]
Suggest why this pH colour chart cannot give an exact value for the pH of the solution of H.
See it on the paper → - 0653/62 · October/November 2022 · Q3b[1]
The student measures the pH of aqueous sodium carbonate. Procedure The student: • adds three drops of universal indicator to aqueous sodium carbonate. The universal indicator turns a blue-purple colour. Fig. 3.2 shows a pH colour chart. colour red orange yellow green dark green blue purple pH 1 4 6 7 8 10 14 Fig. 3.2 E...
See it on the paper → - 0653/62 · October/November 2022 · Q3c(v)[1]
The gas given off is carbon dioxide. Describe the test for carbon dioxide. Include the observation for a positive result. test observation
See it on the paper → - 0653/62 · October/November 2022 · Q3d(ii)[1]
The student concludes that the sample is not sodium carbonate. Explain how the results from the flame test support this conclusion.
See it on the paper →
What examiners said
Many candidates thought that the indicator would turn blue in the presence of an alkali. Some candidates knew that methyl orange is yellow in aqueous calcium hydroxide.
— Examiner report, May/June 2025, 0653/42 Q5(b)(ii) (Cambridge)
The fact that H fizzes when added to a carbonate and turns universal indicator red indicates that H is an acid. Most stated this but some listed all of the observations given in the table, rather than identify the relevant ones that indicate that H is an acid.
— Examiner report, May/June 2025, 0653/61 Q3(b)(ii) (Cambridge)
Candidates found this question challenging. The key point was that the initial colour of aqueous H masked the colour of UI in aqueous H. The best answers identified that the initial colour of aqueous H was blue, but many answers did not make this clear. Candidates often referred to ‘it’ or ‘the solution’ without stating clearly which solution (H or the UI) they meant. Some candidates stated “it is...
— Examiner report, February/March 2025, 0653/62 Q2(c) (Cambridge)
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