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NSS Chemistry Part 3 Metals
HKCEE Past Paper Questions – Structural Questions
1.

HKCEE 1995 Q1
Rubidium (Rb) and potassium belong to the same group in the Periodic Table. The relative atomic mass of rubidium is larger then that of potassium.
(a)

Explain whether rubidium is more reactive than potassium.

(b)

Write a chemical equation for the reaction between rubidium and water. (State symbols should be given.)

(c)

Suggest how rubidium can be stored safely in the laboratory.

(d)

Suggest ONE safety precaution for handling rubidium in the laboratory. (5 marks)

1

2.

HKCEE 1995 Q6b
The table below gives some information about five metals.
Metal Abundance in the Price per kg ($) Relative resistance of earth’s

corrosion

crust (%)

(1 = least resistant

Relative strength of metal
(1 = lowest
3 = highest)

4 = most resistant)
Al

170

3

1

Cu

0.0055

140

3

3

Au

0.0000004

1100000

4

2

Fe

5.0

20

1

3

Zn
(i)

8.1

0.007

160

2

2

Although gold has a very low abundance in the earth’s crust, gold was discovered by man a long time ago. Why?

(ii)

Which of the metals in the above table is the most suitable to make pipes for hot water? Explain your answer.

(iii)

(1)

Aluminium does not corrode easily. Why?

(2)

Aluminium is a principal material for making aircraft but its strength is relatively low. Suggest how the strength of aluminium can be improved to make it suitable for making aircraft.#

(iv)

(1)

Based on the information given in the table, suggest ONE factor that affects the price of a metal.

(2)

Suggest ONE other factor (not indicated in the table) that can also affect the price of a metal. (9 marks)

2

3. HKCEE 1996 Q2
The relative molecular mass of an alkanol X is 60.0. X contains 60% of carbon by mass. (a)

Calculate the number of moles of carbon in one mole of X and hence deduce the molecular formula of X.

(b)

Draw ONE possible structure of X and give its systematic name.

(Relative atomic mass: C = 12.0)
(5 marks)

4. HKCEE 1996 Q4
Briefly describe an experiment, using the following apparatus and materials, to show that air is necessary for the rusting of iron.
2 test tubes, a test tube holder, a Bunsen burner, 2 clean iron nails, paraffin oil and tap water (8 marks)

3

5. HKCEE 1997 Q1a
For each of the tasks listed in the table below, decide which substance on the right is the best to use to accomplish the task. Explain your answer in each case.
Task

Substances

To attach a substance to the iron hull of a
tanker to prevent the hull from rusting.

calcium,
copper,
zinc
(3 marks)

4

6. HKCEE 1997 Q7a
Malachite is a mineral containing copper(II) carbonate and copper(II) hydroxide. It is insoluble in water but reacts with dilute sulphuric acid. The procedure for preparing copper(II) sulphate crystals from malachite is as follows:

Step 1

Pour 50 cm3 of 2M sulphuric acid in a beaker and then warm the acid.

Step 2

Add small portions of powdered malachite to the warm acid while constantly stirring, until effervescence stops and some powdered malachite remains in the beaker.

Step 3

Remove the remaining powdered malachite from the solution.

Step 4

Evaporate the solution slowly to obtain copper(II) sulphate crystals.

(i)

Write a chemical equation for the reaction which causes the effervescence.

(ii)

Why is it necessary to add powdered malachite until some of it remains in the beaker?

(iii)

Draw a labeled diagram to show how the remaining powdered malachite can be removed from the solution.

(iv)

Calculate the theoretical mass of copper(II) sulphate crystals, CuSO4.5H2O, that can be obtained.

(Relative atomic masses: H = 1.0, C = 12.0, O = 16.0, S = 32.1, Cu = 63.5) (8 marks)

5

7. HKCEE 1998 Q8b
The photograph below shows a can of fruit juice. The body of the can is made of iron coated...
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