Question

Gas $A$ is formed on the hydrolysis of calcium cyanamide. The gas can turn moist litmus paper blue and forms a brown precipitate with Nessler's reagent. The gas, $A$ is:

• A. $N_{2}O$
• B. $NO$
• C. $N{O}_2$
• D. $N{H}_3$

Answer 1

Answer: (D)

$N{H}_3$

on hydrolysis of calcium cynamic $CaC{N}_2$

${CaCN}_2+{3H}_{2}O⟶{CaCO}_3+2{NH}_3(\uparrow )$

so the gas formed is $N{H}_3$

$N{H}_3$ Is weakly basics in aqueonum medium

${NH}_3+H_{2}O\rightleftharpoons {NH}_{4}OH\rightleftharpoons {NH}_4^{+}+{OH}^{-}$

so it turned moist red limited blue.

the reaction of$N{H}_3$ with nesslers regreat is

${NH}_3+2K_2{HgI}_4+3KOH⟶H_{2}N-Hg-O-Hg-I+KI+{2H}_{2}O$