Question

$\begin{array}{ccccc}\left[C\right]& \stackrel{CaC{l}_2}{\leftarrow }& \left[A\right]& \underset{\Delta }{\overset{KOH}{\to }}& \left[B\right]\\ & & Colourless& & Gas,giving\\ & & salt& & whitefumeswithHCl\end{array}$
White ppt. $\left[C\right]$ decolorizes pink color of acidified $KMn{O}_4$, then $\left[A\right]$ is :

• A. $N{H}_{4}CI{O}_4$
• B. $N{H}_{4}N{O}_2$
• C. ${\left(N{H}_4\right)}_2{C}_2{O}_4$
• D. ${\left(N{H}_4\right)}_{2}S{O}_4$

Answer 1

The correct option is C ${\left(N{H}_4\right)}_2{C}_2{O}_4$

Option (C) is correct.

[A] is $(N{H}_4{)}_2{C}_2{O}_4$ contains ammonium and oxalate ions.

$N{H}_4^{+}$ gives white fumes of $N{H}_{4}Cl$ with $HCl$.

$C_2{O}_4^{2-}$ gives white ppt. of calcium oxalate with $CaC{l}_2$ and it decolorizes pink color of acidified $KMn{O}_4$.