Highly soluble hydroxide in water is formed by -

1. Ni²⁺

2. K⁺

3. Zn²⁺

4. Al³⁺

The strongest reducing agent among the following is:

1. K

2. Na

3. Al

4. Mg

When crystal of caustic soda is exposed to air, a liquid layer is deposited because:

1. crystal melts

2. crystal loses water

3. crystal absorbs moisture and CO₂

4. crystal sublimes

Brine is chemically:

1. conc. solution of Na₂CO₃

2. conc. solution of Na₂SO₄

3. conc. solution of NaCl

4. conc. solution of alum

Alkali metals are characterised by:

1. Good conductors of heat and electricity.

2. High melting points.

3. Low oxidation potentials.

4. High ionisation potentials.