classification of elements, chemical bonding, periodicity in properties & physical transformation - Category wise Question and Answer Practice Test with Solutions

Question : 26 [CDS ]

Which one of the following properties changes with valency?

a) Equivalent weight

b) Molecular weight

c) Atomic weight

d) Density

Question : 27 [PSC (Pre) 2018]

The technique of chromatography is used to

a) Determine the structure of substances

b) Dry distillation of colouring substances

c) Identify colour substances

d) Separate the substances from a mixture

Question : 28

In an attempt to demonstrate electrical conductivity through an electrolyte, the following apparatus (Fig.) was set up. Which among the following statement(s) is (are) correct?

1. Bulb will not glow because electrolyte is not acidic
2. Bulb will glow because NaOH is a strong base and furnishes ions for conduction.
3. Bulb will not glow because circuit is incomplete
4. Bulb will not glow because it depends upon the type of electrolytic solution

a) 2 only

b) 1 and 3

c) 2 and 4

d) 4 only

Question : 29

Identify the incorrect statements regarding entropy.

1. At absolute zero temperature, entropy of a perfectly crystalline substance is taken to be zero.
2. At absolute zero temperature, the entropy of a perfectly crystalline substance is positive.
3. Absolute entropy of a substance cannot be determined.
4. At 0°C, the entropy of a perfectly crystalline substance is taken to be zero

a) 1, 2 and 4

b) 1, 2 and 3

c) 1, 3 and 4

d) 2, 3 and 4

Question : 30 [CDS]

Which one of the following when dissolved in H₂ O gives hissing sound?

a) Slaked lime

b) Sodalime

c) Limestone

d) Quicklime