HKCEE and HKAL Past Paper Questions
1. HKCEE 1994 Q8b
A student carried out some tests on an ionic compound X which was a white solid. The results obtained were summarized in the following flow diagram:
Based on the above information, deduce the cation and anion present in X.
Describe how the flame test on X can be carried out in the laboratory.
2. HKCEE 1995 Q2
In each of the following groups of substances, there is ONE substance which is different from the other in terms of their properties. In each group, identify the substance which is different from the others and explain your choice.
argon, fluorine, helium, neon
nylon, perspex, polyethene, urea-methanal
milk of magnesia, soap, vinegar, window cleaner
carbon monoxide, hydrogen, methane, nitrogen
3. HKCEE 1996 Q6b
A, B, C and D are four unlabelled bottles, each containing one of the following reagents:
2M ammonia solution, 2M ethanoic acid,
2M hydrochloric acid, 2M nitric acid
The following scheme is used to identify the four reagents:
What is the reagent in bottle A? Explain why this reagent turns red litmus paper blue.
What is the reagent in bottle B? Write a chemical equation for the reaction between this reagent and copper
turnings, and a chemical equation for the formation of the brown fumes.
Suggest a test to distinguish between the reagent in bottles C and D.
(Smelling the reagents in NOT an acceptable answer.)
State the observable change in this test and explain your answer.
4. HKCEE 1998 Q5
Each of five unlabelled bottles contains one of the following chemicals:
2 M hydrochloric acid
2 M nitric acid
2 M sodium chloride solution
2 M sodium hydroxide solution
Suggest how you would carry out tests to identify the