UNIT 4: Hydrogen - Online Test

Q1. Which of the following statements about hydrogen is incorrect ?
Answer : Option C
Explaination / Solution:

Correct statement : Hydrogen has three isotopes of which protium is the most common.

Q2. Water gas is
Answer : Option C
Explaination / Solution:

CO + H2 - Water gas

Q3. Which one of the following statements is incorrect with regard to ortho and para dihydrogen ?
Answer : Option B
Explaination / Solution:

Correct statement : Ortho isomer - one nuclear spin

Para isomer - zero nuclear spin


Q4. Ionic hydrides are formed by
Answer : Option D
Explaination / Solution:

eg : Sodium hydride (Na+ H)

Q5. Tritium nucleus contains
Answer : Option C
Explaination / Solution:

1T3 (1e, 1p, 2n)

Q6. Non-stoichiometric hydrides are formed by
Answer : Option A
Explaination / Solution:
No Explaination.


Q7.

Assertion : Permanent hardness of water is removed by treatment with washing soda.

Reason : Washing soda reacts with soluble calcium and magnesium chlorides and sulphates in hard water to form insoluble carbonates
Answer : Option A
Explaination / Solution:

Ca2+ + Na2CO3 → CaCO3 ↓ + 2Na+

Q8. If a body of a fish contains 1.2 g hydrogen in its total body mass, if all the hydrogen is replaced with deuterium then the increase in body weight of the fish will be
Answer : Option A
Explaination / Solution:

mass of deuterium = 2 × mass of protium

If all the 1.2 g hydrogen is replaced with deuterium, the weight will become 2.4g. Hence the increase in body weight is (2.4 – 1.2 = 1.2 g)


Q9. The hardness of water can be determined by volumetrically using the reagent
Answer : Option D
Explaination / Solution:
No Explaination.


Q10. The cause of permanent hardness of water is due to
Answer : Option C
Explaination / Solution:

Permanent hardness if water is due to the presence of the chlorides, nitrates and sulphates of Ca2+ and Mg2+ ions.