Chemistry

Problem

When a crystalline compound

X

is heated with

\text{K}_2\text{Cr}_2\text{O}_7

and concentrated

\text{H}_2\text{SO}_4

, a reddish brown gas

A

is evolved. On passing

A

into caustic soda, a yellow solution of

B

is formed. A yellow precipitate of

C

is obtained when a solution of

B

is neutralised with acetic acid and then treated with a lead acetate solution. When

X

is heated with

\text{NaOH}

, a colourless gas is evolved which, when passed into a solution of

\text{K}_2[\text{HgI}_4]

, gives a reddish brown precipitate of

D

. Which of the following is the composition of the brown precipitate (

D

)? a.

\text{HgI}_2

\text{Hg}(\text{NH}_2)_2\text{I}

\text{HgO}

\text{HgO} \cdot \text{Hg}(\text{NH}_2)_2\text{I}