Common table salt becomes moist and does not pour easily in rainy season because:

1. It contains magnesium chloride.

2. It contains magnesium carbonate.

3. It melts slightly in rainy season.

4. Sodium chloride is hygroscopic.

A  mixture of Al(OH)₃ and Fe(OH)₃ can be separated easily by treating it with:

1. HCl

2. NH₄OH

3. HNO₃

4. NaOH

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

Which has lowest thermal stability?

1. Li₂CO₃

2. Na₂CO₃

3. K₂CO₃

4. Rb₂CO₃

An alkali metal that reacts with nitrogen to form nitride is -

1. Li

2. Na

3. Cs

4. None of the above.

Caustic soda is:

1. Efflorescent

2. Deliquescent

3. Hygroscopic

4. Oxidant

The most basic oxide among the following is:

1. Na₂O

2. BaO

3. As₂O₃

4. Al₂O₃

Pearl ash and caustic potash are chemically:

1. K₂CO₃ and KOH

2. KOH and K₂CO₃

3. Na₂CO₃ and KOH

4. Na₂CO₃ and NaOH

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

1. Zn

2. Fe

3. K

4. Al

Which is industrially prepared by the electrolysis of aqueous NaCl?

1. Na₂CO₃

2. NaHCO₃

3. NaOH 

4. NaOCl