Sodium metal cannot be stored under:

1. benzene

2. kerosene

3. alcohol

4. toluene

The alkali metal which acts as a nutrient for plants is:

1. Na

2. K

3. Li

4. Rb

The element which does not dissolve in caustic soda is:

1. silicon

2. aluminium

3. zinc

4. cadmium

Lithium is the only alkali metal which is not placed in kerosene but is wrapped in paraffin wax, because:

1. it reacts with kerosene

2. it floats to the surface of kerosene because of low density

3. it does not react with air and H₂O

4. none of the above

Manufacture of NaOH is done by:

1. Castner - Kellner process

2. Solvay process

3. Brine process

4. Mond's process

Which one is the highest melting point halide?

1. NaCl

2. NaBr

3. NaF

4. NaI

KO₂ is used in oxygen cylinder in space air craft and submarines because it:

1. absorbs CO₂ and increase O₂ content

2. eliminate moisture

3. absorbs CO₂

4. produces O₂

The products of the electrolysis of aqueous solution of common salt are:

1. Na + Cl₂

2. H₂ + O₂

3. NaOH + H₂ + Cl₂

4. NaOH + Cl₂ + O₂

The most dangerous method of precipitating hydrogen would be by the action of HCl on:

1. Zn

2. Fe

3. K

4. Al

Excess of dilute sodium hydroxide solution is gradually added with shaking to an aqueous solution of zinc sulphate. What would you observe?

1. A light blue precipitate is first formed which finally dissolves to give a deep blue solution

2. A white precipitate appears which dissolves to give a colourless solution.

3. A white precipitation is formed which does not dissolve 

4. No change takes place and the solution remains clear