Density of water is maximum at:

1. 0$°$C

2. 100 $°$C

3. 4$°$C

4. 0 K

Atomic hydrogen is obtained by:

1. electrolysis of heavy water

2. reaction of water with heavy metals

3. thermal decomposition of water

4. passing silent electric discharge through hydrogen at low pressure

Permutit is:

1. hydrated sodium aluminium silicate

2. sodium hexa meta-phosphate

3. sodium silicate

4. sodium meta-aluminate

Hydrogen is not obtained when zinc reacts with:

1. cold water

2. dil. H₂SO₄

3. dil HCl

4. hot 20% NaOH

The volume strength of 1.5N H₂O₂ Solution is :

1. 4.8

2. 8.4

3. 3.0

4. 8.0

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

Para hydrogen at room temperature is:

1. Less stable than ortho hydrogen.

2. More stable than ortho hydrogen.

3. As stable as ortho hydrogen.

4. None of the above.

Hydrogen combines directly with:

1. Ca

2. Cu

3. Zn

4. Fe

Acidified solution of chromic acid on treatement with H₂O₂ yields :

1. ${\mathrm{CrO}}_3 + {\mathrm{H}}_2\mathrm{O} + {\mathrm{O}}_2$

2. ${\mathrm{Cr}}_2{\mathrm{O}}_2 + {\mathrm{H}}_2\mathrm{O} + {\mathrm{O}}_2$

3. ${\mathrm{CrO}}_5 + {\mathrm{H}}_2\mathrm{O} + {\mathrm{K}}_2{\mathrm{SO}}_4$

4. ${\mathrm{H}}_2{\mathrm{Cr}}_2{\mathrm{O}}_7 + {\mathrm{H}}_2\mathrm{O} + {\mathrm{O}}_2$

What is formed when calcium carbide reacts with heavy water?

1. C₂D₂

2. CaD₂

3. Ca₂D₂O

4. CD₂