KVPY Sample Paper KVPY Stream-SX Model Paper-31

A colourless water soluble solid 'X' on heating gives equimolar quantities of Y and Z, Y gives dense white fumes \[HCl\] and Z does so with \[N{{H}_{3}}\] Y gives brown precipitate with Nessler's reagent and Z gives white precipitate with nitrates of \[A{{g}^{+}},\]\[P{{b}^{2+}}\] and \[H{{g}^{+}}\] 'X' is-

A) \[N{{H}_{4}}Cl\]

B) \[N{{H}_{4}}N{{O}_{3}}\]

C) \[N{{H}_{4}}N{{O}_{2}}\]

D) \[FeS{{O}_{4}}\]

Correct Answer: A

Solution :

\[N{{H}_{4}}Cl\xrightarrow{\Delta }\underset{Y}{\mathop{N{{H}_{3}}}}\,+\underset{Z}{\mathop{HCl}}\,\]

\[N{{H}_{3}}+2{{K}_{2}}[Hg{{I}_{4}}]+3KOH\to {{H}_{2}}NHgO.\]

\[HgI+7KI+{{H}_{2}}O\]

Nessler's reagent brown ppt. iodide of Millon's base