CIE Chemistry (US-0439): Specimen Questions with Answers 126 - 128 of 240

Question number: 126

MCQ▾

Question

Which of the following is Not a good absorber of sound?

Choices

Choice (4) Response

a.

Curtains

b.

Wooden doors

c.

Metal Cupboards

d.

Cushions

Answer

c.

Explanation

  • Correct option is C because Soundproofing is any means of reducing the sound pressure with respect to a specified sound source and receptor.

  • There are several basic approaches to reducing sound: increasing the distance between source and receiver, using noise barriers to reflect or absorb the energy of the sound waves, using damping structures such as sound baffles, or using active antinoise sound generators. And metal cupboard comes under category of sound proofing.

Question number: 127

MCQ▾

Question

Lanthanides and actinides are ________ in nature.

Choices

Choice (4) Response

a.

Metallic

b.

Non metallic

c.

Question does not provide sufficient data or is vague

d.

All of the above

Answer

a.

Explanation

Lanthanides and Actinides are metallic in nature.

Question number: 128

MCQ▾

Question

1 mole of any gaseous substance occupies ________ litres at S. T. P.

Choices

Choice (4) Response

a.

22.4

b.

c.

None of the above

d.

Question does not provide sufficient data or is vague

Answer

a.

Explanation

  • Molar volume of a gas is the volume occupied by 1 mole of gas at the standard temperature and pressure (S. T. P. ). One mole of a gas occupies litres or at S. T. P.

  • S. T. P means standard temperature and pressure. At S. T. P. , the value of temperature is or and that of pressure is of Hg or .

  • Thus one mole of any substance occupies litres at standard temperature and pressure.