Hydrogen

The element used for welding metals with high melting points is

1. He
2. Cl2
3. H2
4. Ne

Tritium, a radioactive isotope of hydrogen, emits which of the following particles?

1. Neutron (n)
2. Beta ( -)
3. Alpha ( )
4. Gamma ( )

Match the following and identify the correct option.

1. (a)-(iii), (b)-(ii), (c)-(i), (d)-(iv)
2. (a)-(iii), (b)-(iv), (c)-(ii), (d)-(i)
3. (a)-(i), (b)-(iii), (c)-(ii), (d)-(iv)
4. (a)-(iii), (b)-(i), (c)-(ii), (d)-(iv)

The method used to remove temporary hardness of water is :

1. Ion-exchange method
2. Synthetic resins method
3. Calgon’s method
4. Clark’s method

Among CaH2, BeH2, BaH2, the order of ionic character is

1. BeH2 < CaH2 < BaH2
2. CaH2 < BeH2 < BaH2
3. BeH2 < BaH2 < CaH2
4. BaH2 < BeH2 < CaH2

Which of the following statements about hydrogen is incorrect?

1. Hydronium ion, H3O+ exists freely in solution.
2. Dihydrogen does not act as a reducing agent.
3. Hydrogen has three isotopes of which tritium is the most common.
4. Hydrogen never acts as cation in ionic salts.

(I) H2O2 + O3 H2O + 2O2 (II) H2O2 + Ag2O 2Ag + H2O + O2 Role of hydrogen peroxide in the above reactions is respectively

1. oxidizing in (I) and reducing in (II)
2. reducing in (I) and oxidizing in (II)
3. reducing in (I) and (II)
4. oxidizing in (I) and (II)

Some statements about heavy water are given below: Which of the above statements are correct?

1. (i) and (ii)
2. (i), (ii) and (iii)
3. (ii) and (iii)
4. (i) and (iii)

Which one of the following molecular hydrides acts as a Lewis acid?

1. NH3
2. H2O
3. B2H6
4. CH4

The structure of H2O2 is

1. spherical
2. non-planar
3. planar
4. linear