In the preparation of hydrogenated oil the chemical reaction involved is called as-

1. Hydrogenation

2. Reduction

3. Dehydration

4. Oxidation

The most abundant isotope of hydrogen is-

1. Tritium

2. Deuterium

3. Protium

4. Para-hydrogen

Hydrogen is evolved by the action of cold dilute HNO₃ on:

1. Fe

2. Mg or Mn

3. Cu

. Al

Hydrogen is not obtained when zinc reacts with:

1. cold water

2. dil. H₂SO₄

3. dil HCl

4. hot 20% NaOH

Very pure hydrogen (99.9%) can be made by which of the following processes ?

1. Mixing natural hydrocarbons of high molecular weight

2. Electrolysis of water

3. Reaction of salt like hydrides with water

4. Reaction of methane with steam