The hydrides of carbon (C_nH_{2n + 2}) can act as -

1. Lewis acid.

2. Lewis base.

3. Both 1 and 2

4. None of the above

“Non-stoichiometric hydrides” are :

Metallic hydrides are useful for hydrogen storage because : 

1. Metallic hydrides are oxygen-rich.

2. Metallic hydrides are oxygen-deficient.

3. Metallic hydrides are hydrogen-rich.

4. Metallic hydrides are hydrogen-deficient.

Atomic hydrogen or oxy-hydrogen torch is used for cutting and welding purposes because:

 The correct order of hydrogen bonding among ${\mathrm{NH}}_3$, H2O and HF, is 

1. HF > ${\mathrm{H}}_2\mathrm{O}$ > ${\mathrm{NH}}_3$

2. ${\mathrm{H}}_2\mathrm{O}$ > HF > ${\mathrm{NH}}_3$

3. HF > ${\mathrm{NH}}_3$ > ${\mathrm{H}}_2\mathrm{O}$

4. ${\mathrm{NH}}_3$ > HF > ${\mathrm{H}}_2\mathrm{O}$

CO2  is used as a fire extinguisher because -

1. ${\mathrm{CO}}_2$ has high lattice energy.

2. ${\mathrm{CO}}_2$ will be effective in isolating the burning surface from dihydrogen and dioxygen.

3. ${\mathrm{CO}}_2$ is lighter than dioxygen.

4. ${\mathrm{CO}}_2$ is lighter than dihydrogen.

The term ’auto-protolysis’ of water means :

The correct statement about the reaction of water with fluorine is:

The structure of the common form of ice is :

The softening of hard water by synthetic ion-exchange resins is based on -

1. Increasing the lattice energy.

2. Physical separation.

3. Lowering the activation energy.

4. Exchange of cations and anions.