A white crystalline solid A on boiling with caustic soda solution gave a colourless gas B which when passed through an alkaline solution of potassium mercurio iodide gave a brown ppt. The substance A on heating gave a gas C which rekindled a glowing splinter but did not give brown fumes on air oxidation. The gas B is

A white crystalline solid A on boiling with caustic soda solution gave

1.	A white crystalline solid A on boiling with caustic soda solution gave a colourless gas B which when passed through an alkaline solution of potassium mercurio iodide gave a brown ppt. The substance A on heating gave a gas C which rekindled a glowing splinter but did not give brown fumes on air oxidation. The gas B is
Answer» `H_2 S ` `NH_3` `HCl` `CO_2` Solution :Substance A is `NH_4 NO_3` which on BOILING with NaOH gives `NH_(3)` (gas B) `NH_(4) NO_(3) + NaOH to NaNO_(3)+ NH_(3) + H_(2) O` `NH_(3)` gives brown ppt. with Nessler.s REAGENT `(K_2 HgI_4)` `2K_2 [HgI_4] + NH_(3) + 3 KOH to H_(2) underset("Brown ppt.")(N.HgO.) HgI + 7 KI + 2H_(2)O` Substance A on heating gives `N_2O` (gas C) which rekindles GLOWING SPLINTER but is not converted into `NO_2` by air OXIDATION . `NH_4 NO_(3) overset(Delta)(to) N_2 O + 2 H_(2)O`