Question

Which of the following is correct about lunar caustic?

• A. When it is heated to its melting point, it decomposes to $Ag$, $N{O}_2$ and $O_2$
• B. When it is heated till it gets red hot, it decomposes to $AgN{O}_2$ and $O_2$
• C. It is prepared by reacting silver with nitric acid
• D. When it is treated with $KI$ solution, it gives a yellow coloured compound which does not dissolve in $KCN$ solution

Answer 1

The correct option is C It is prepared by reacting silver with nitric acid

$AgN{O}_3$ is called lunar caustic especially when fused and molded into sticks for use as a caustic.
(a) When it is heated to its melting point, it decomposes to $AgN{O}_2$ and $O_2$.
(b) When it is heated till it is red hot, it decomposes to $Ag,N{O}_2$ and $O_2$.
(d) When it is treated with $KI$ solution, it gives $AgI$, a yellow coloured compound which dissolves in KCN solution to give $K\left[Ag\right(CN{)}_2]$.