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.

The incorrect statement among the following options is:

1. K⁺ ions react with alkaline water and give K(OH)₃

2. KCl is a salt of strong acid and strong base.

3. Al(OH)₃ in alkaline condition gives [Al(OH)₄]^-

4. AlCl₃ is a salt of strong acid and weak base.