pH of a saturated solution of Ba(OH)₂ is 12. The value of solubility product (K_sp) of Ba(OH)₂ is

In qualitative analysis, the metals of group I can be separated from other ions by precipitating them as chloride salts. A solution initially contains Ag⁺ and pb²⁺ at a concentration of 0.10 M. Aqueous HCl is added to this solution until the Cl^$$-$$ concentration is 0.10 M. What will the concentrations of Ag⁺ and Pb²⁺ be at equilibrium ?

(K_sp for AgCl = 1.8 $$ \times $$ 10^$$-$$10, K_sp for PbCl₂ = 1.7 $$ \times $$ 10^$$-$$5)

Which of the following is least likely to behave as Lewis base?

A buffer solution is prepared in which the concentration of NH₃ is 0.30 M and the concentration of NH⁺₄ is 0.20 M. If the equilibrium constant, K_b for NH₃ equals 1.8 $$ \times $$ 10^$$-$$5, what is the pH of this solution? (log 2.7 = 0.43)