Question

$C{O}_2$ gas along with solid $\left(Y\right)$ is obtained when sodium salt $\left(X\right)$ is heated. $\left(X\right)$ is again obtained when $C{O}_2$ gas is passed into aqueous solution of $\left(Y\right)$. $\left(X\right)$ and $\left(Y\right)$ respectively are :

• A. $N{a}_{2}C{O}_3$ and $N{a}_{2}O$
• B. $N{a}_{2}C{O}_3$ and $NaOH$
• C. $NaHC{O}_3$ and $N{a}_{2}C{O}_3$
• D. $N{a}_{2}C{O}_3$ and $NaHC{O}_3$

Answer 1

Answer: (C)

$NaHC{O}_3$ and $N{a}_{2}C{O}_3$

Reactions:
$NaHC{O}_3\stackrel{heat}{\to }N{a}_{2}C{O}_3+H_{2}O+C{O}_2$
And sodium carbonate again forms bicarbonate in excess of $C{O}_2$.
$N{a}_{2}C{O}_3+C{O}_2+H_{2}O\to NaHC{O}_3$
So, it's a reversible process.