Which of the following salt solutions turns red litmus blue?

The solubility product of $$\mathrm{PbCl}_2$$ at $$298 \mathrm{~K}$$ is $$3.2 \times 10^{-5}$$. What is its solubility in $$\mathrm{mol} \mathrm{dm}{ }^{-3}$$ ?

Identify base$$_2$$ for following equation according to Bronsted-Lowry theory.

$$\mathrm{HCl}_{(\mathrm{aq})}+\mathrm{H}_2 \mathrm{O}_{(l)} \rightleftharpoons \mathrm{H}_3 \mathrm{O}_{(\mathrm{aq})}^{+}+\mathrm{Cl}_{(\mathrm{aq})}^{-}$$

An organic monobasic acid has dissociation constant $$2.25 \times 10^{-6}$$. What is percent dissociation in its $$0.01 \mathrm{~M}$$ solution?