Answer
Please see the work below.
Work Step by Step
We know that:
(a) As the salts formed, $Na_2SO_4$ and $Cu(NO_3)_2$, are both in aqueous form, no precipitate is formed.
(b) The precipitate formed is $BaSO_4$, and the reaction is:
${BaCl_2}_{(aq)}+{K_2SO_4}_{(aq)} \rightarrow {BaSO_4}_{(aq)}+2KCl_{(aq)}$
