When CO₂ is bubbled into an aqueous solution of Na₂CO₃, the following is formed:

1. H₂O

2. OH-

3. NaHCO₃

4. NaOH

The element which does not dissolve in caustic soda is:

1. silicon

2. aluminium

3. zinc

4. cadmium

The principal products obtained on heating iodine with concentrated caustic soda solution are:

1. NaOI + NaI

2. NaIO₃ + Nal

3. NaOI + NaIO₃ + NaI

4. NaIO₄ + NaI

The formula of washing soda is:

1. Na₂CO₃

2. Na₂CO₃.H₂O

3. Na₂CO₃.7H₂O

4. Na₂CO₃.10H₂O

When sulphur is heated with NaOH(aq) the compounds formed are:

(1) Na₂S + H₂O

(2) Na₂SO₃ + H₂O

(3) Na₂S + Na₂S₂O₃ + H₂O

(4) Na₂S₂O₃ + H₂O

NaOH is prepared by the electrolysis of:

1. aqueous solution of sodium chloride with platinum electrodes

2. molten sodium chloride with graphite anode and iron cathodes

3. sodium carbonate with platinum electrodes

4. sodium carbonate with nickel electrodes

Fusion of AgCl with Na₂CO₃ gives:

1. Ag₂CO₃

2. silver carbide

3. Ag

4. Ag₂

Which of the following acts as reducing agent as well as oxidising agent?

1. Na₂O

2. Na₂O₂

3. NaNO₃

4. KNO₃

Nitrates of I group (except LiNO₃) on heating give:

1. O₂

2. N₂

3. NO

4. NO₂

Indian saltpetre is:

1. KNO₃

2. NaNO₃

3. NaCl

4. Na₂CO₃