Question

Identify (A), (B) and (C).

• A. (A): $N{a}_{2}S$ (B): $N{a}_2\left[Fe\right(NC{)}_{5}NOS]$ (C): $CdO$
• B. (A): $Na{O}_2$ (B): $N{a}_2\left[Fe\right(CN{)}_{5}NOS]$ (C): $CdS$
• C. (A): $N{a}_{2}S$ (B): $N{a}_2\left[Fe\right(CN{)}_{5}NOS]$ (C): $CdS$
• D. (A): $N{a}_{2}O$ (B): $N{a}_2\left[Fe\right(NC{)}_{5}NOS]$ (C): $PbS$

Answer 1

Answer: (C)

(A): $N{a}_{2}S$ (B): $N{a}_2\left[Fe\right(CN{)}_{5}NOS]$ (C): $CdS$

$N{a}_{2}S{O}_4\left(s\right)+2C\left(s\right)\to N{a}_{2}S\left(s\right)+2C{O}_2\left(g\right)$.

$A$ will be $N{a}_{2}S$.
$N{a}_{2}S+N{a}_2\left[Fe\right(CN{)}_{6}NO]\to N{a}_{2}Fe(CN{)}_{5}NOS]$.

B will be $N{a}_2\left[Fe\right(CN{)}_{5}NOS]$
$N{a}_{2}S+CdC{O}_3\to CdS+N{a}_{2}C{O}_3$.

$C$ will be $CdS$.
Hence option $C$ is the correct answer.