Consider the following reactions.
$ \text{PbCl}_2 + \text{K}_2\text{CrO}_4 \rightarrow \text{A} + 2\text{KCl} $
(Hot solution)
$ \text{A} + \text{NaOH} \rightleftharpoons \text{B} + \text{Na}_2\text{CrO}_4 $
$ \text{PbSO}_4 + 4\text{CH}_3\text{COONH}_4 \rightarrow (\text{NH}_4)_2\text{SO}_4 + \text{X} $
In the above reactions, A, B and X are respectively.
