CIE Chemistry Paper-1: Specimen Questions 19 - 20 of 99

Question number: 19

MCQ▾

Question

Which alloy contains non-metal as its constituents?

Choices

Choice (4) Response
a.

Amalgam

b.

Steel

c.

Brass

d.

Bronze

Answer

b.

Explanation

Steels are alloys of iron and other elements, primarily carbon, widely used in construction and other applications. The carbon content of steel is between 0.002 % and 2.1 % by weight for plain iron-carbon alloys. These values vary depending on alloying elements such as manganese, chromium, nickel, iron, tungsten, carbon and so on. Basically, steel is an iron-carbon alloy.

Question number: 20

MCQ▾

Question

Aluminium is an important metal with many uses. Its properties are:

1 It is a good conductor of heat.

2 It has a low density.

3 It has an oxide layer that prevents corrosion.

What explains the use of aluminium for cooking and storing food?

Choices

Choice (4) Response
a.

1 and 2 only

b.

1, 2 and 3

c.

2 and 3 only

d.

1 only

Answer

b.

Explanation

Aluminium is now the second most widely used metal in the world. The above properties can be explained as:

  • Aluminium is an excellent conductor of heat and electricity. An aluminium conductor weighs approximately half as much as a copper conductor having the same conductivity.
  • With a density one third that of steel, 2.700 kg/m3. The low density of aluminium accounts for it being lightweight but this does not affect its strength.
  • Aluminium reacts with the oxygen in the air to form an extremely thin layer of oxide. This layer is dense and provides excellent corrosion protection. The layer is self-repairing if damaged.

Therefore all the above three properties are useful.

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