CIE Chemistry (US-0439): Specimen Questions with Answers 173 - 175 of 240

Question number: 173

Short Answer Question▾

Write in Short

Give another example of a substance other than a metal which, when finely powdered, might explode when ignited in air.

[1 Marks]

Explanation

Another example is water-reactive as well and will ignite when they contact water or humid air. They can be handled safely in atmospheres of argon or (with a few exceptions) nitrogen.

Question number: 174

MCQ▾

Question

________ acid is used as a cleansing agent in galvanization mixtures and for preparing some bathroom cleansing agent and in a large concentration emits fumes of chlorine gas.

Choices

Choice (4) Response

a.

Sulphuric acid

b.

Hydrochloric acid

c.

Acetic acid

d.

Carbonic acid

Answer

b.

Explanation

Hydrochloric acid is used as a cleansing agent in galvanization mixtures and for preparing some bathroom cleansing agent and in a large concentration emits fumes of chlorine gas.

Question number: 175

MCQ▾

Question

1 mole of a substance occupies a volume of

Choices

Choice (4) Response

a.

b.

c.

d.

All a. , b. and c. are correct

Answer

d.

Explanation

  • The molar volume of a gas is 22.4 liters at STP (standard temperature and pressure).

  • The molar volume of gas is at RTP (room temperature and pressure).

Image of the molar volume

Image of the Molar Volume

Image of the molar volume

Image of the molar volume, STP

Image of the Molar Volume, STP

Image of the molar volume, STP