Explanation

(d)
$\begin{matrix}
Ag_{2}CO_{3} \\
276g
\end{matrix} \longrightarrow \begin{matrix}
2Ag \\
216g
\end{matrix} + CO_{2} + \frac{1}{2}O_{2}$
As 276 g of $Ag_{2}CO_{3}$ will give = 216g of Ag
So, 2.76 g of A$g_{2}CO_{3}$ will give $= \frac{2.76 \times 216}{276} = 2.16$g