Question

Sodium nitroprusside when added to an alkaline solution of sulphide ions produces a purple coloured complex. What is the total number of sodium atoms present per molecule in this purple coloured complex?

Answer 1

Sodium nitroprusside $\left(N{a}_2\right[Fe\left(CN{)}_{5}NO\right])$ when added to an alkaline solution of sulphide ions produce a purple coloured complex which is $N{a}_4\left[Fe\right(CN{)}_{5}NOS]$.

The total number of sodium per molecule in this purple coloured complex is $4$.

The reaction is as follows:

$N{a}_2\left[Fe\right(CN{)}_{5}NO]+N{a}_{2}S\to N{a}_4[Fe\left(CN{)}_{5}NOS\right]$