On adding dilute HCl acid to copper oxide powder, the solution formed is blue-green. Predict the new compound formed which imparts a blue-green colour to the solution.

3

(a)

Name a major ore from which iron is extracted. Write chemical equations for the reactions that take place in the blast furnace for the extraction of iron from this ore.

3

(a)

(i) Name an important oxide ore of iron.
(ii) Describe the extraction of iron from those ore under the following heads:
(a) Reduction of the concentrated ore
(b) Diagram of the furnace used
(c) Chemical equations for the reactions involved

3

(a)

Give reasons for the following :
(i) Metals are regarded as electro-positive elements
(ii) When a piece of copper metal is added to a solution of zinc sulphate, no change takes place, but the blue colour of copper sulphate fades away when a piece of zinc is placed in its solution.
(iii) Articles made of alimunium do not corrode even though aluminium is an active metal.

3

(a)

From amongst the metals sodium, calcium, aluminium, copper and magnesium, name the metal.
(i) which reacts with water only on boiling and
(ii) another which does not react even with steam.

3

(a)

Why do ionic compounds conduct electricity?

3

(a)

What are 'mineral' and 'ore'?

3

(a)

State five points of differences between ionic compound and covalent compound.

3

(a)

Point out any 3 differences between calcination and roasting.

3

(a)

(i) A non-metal X exists in two different forms Y and Z. Y is the hardest natural substance whereas Z is a good conductor of electricity. Identity X, Y, Z.
(ii) A element, X, on reaction with oxygen forms an oxide XO₂. The oxide when dissolved in water turns blue litmus red. State whether element X is a metal or a non-metal.
(iii) Name the metal which is alloyed with copper to make bronze.

3

(a)

Write three differences between metals and non-metals on the basis of chemical properties.

3

(a)

State reason for the following:
(i) Non-metals cannot displace hydrogen from the acids.
(ii) Hydrogen is not a metal, yet it is placed in the activity series of metals.
(iii) Aluminium is more reactive than iron, yet its corrosion is less than that of iron

3

(a)

Write the balanced chemical equation for the following reactions:
(i) When copper is heated in air.
(ii) When aluminum is heated in air.
(iii) Aluminium oxide reacts with sodium hydroxide.

3

(a)

Describe an activity to show that the rusting of iron occurs in the presence of air and moisture.

3

(a)

You are given samples of three metals: Sodium, magnesium and copper. Suggest any two activities to arrange them in order to their decreasing reactivity

3

(a)