The ionization constant of ammonium hydroxide is 1.77 x 10^-5 at 298 K. Hydrolysis constant of ammonium Chloride is:

1. 5.65 x 10^-10

2. 6.50 x 10^-12

3. 5.65 x 10^-13

4. 5.65 x 10^-12

A weak acid, HA, has a K_a of 1.00×10^-5. If 0.100 mole of this acid is dissolved in one litre of water, the percentage of acid dissociated at equilibrium is closest to:

1. 99.0%

2. 1%

3. 99.9%

4. 0.100%