The ortho and para hydrogen possess:

1. same physical properties but different chemical properties

2. different physical properties but same chemical properties

3. same chemical and physical properties

4. different physical and chemical properties

On bubbling CO₂ through a solution of barium peroxide in water:

1. O₂ is formed

2. H₂CO₃ is formed

3. H₂O₂ is formed

4. H₂ is formed

A mixture of hydrazine and 60 to 90 percent of H₂O₂ solution is:

1. antiseptic

2. rocket fuel

3. germicide

4. insecticide

A given solution of H₂O₂ is 30 volume. Its concentration in terms of molarity is:

1. 9.1 M

2. 2.68 M

3. 2.5 M

4. 26.8 M

The decomposition of H₂O₂ is accelerated by:

1. traces of acids

2. finely divided metals

3. acetanilide

4. alcohol

 Hardness of water cannot be removed by -

1. Clark's method

2. Adding washing soda

3. Calgon process

4. Filtration

At pH = X, \(\text{CrO}_4^{2-}\)​ (yellow) changes to \(\text{Cr}_2\text{O}_7^{2-}\) (orange), and vice versa at pH = Y.
What are the values of X and Y, respectively?

1. 6, and 8

2. 6, and 5

3. 8, and 6

4. 7, and 7

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

Hydrogen combines directly with:

1. Ca

2. Cu

3. Zn

4. Fe

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.