A mixture consist of a yellow solid [A] and colourless solid [B] which given lilac colour in flame. The miture given a black precipiate [C] on passing `H_(2)S` gas. The precipitate [C] is soluble in aqura region and on evaporating and on adding `SnCl_(2)`, gives greyish black precipitate [D]. The misture solution on reacing with `NH_(4)OH` gives a brown precipiates. The sodium extract of the mixture with `C Cl_(4)//FeCl_(3)` given violet layer. The extract also given yellow precicitate with `AgNO_(3)` solution which is insoluble in `NH_(3)`.
The greyish black precipitate [D] is of

Options

A. mercury
B. silver
C. lead
D. None of these

Answer

A

Explanation

(a) In aqua regia, `HgI_(2)` is converted to `HgCl_(2)` which is then reduced by `SnCl_(2)` to mercury [D] which is greyish black in colour `HgCl_(2)+SnCl_(2)rarrunderset("black[D]")underset("Greyish")(Hg)+SnCl_(4)`