Assertion : Stannous chloride gives grey precipitate with mercuric chloride , but stannic chloride does not do so.
Reason : Stannous chloride is a powerful oxidising agent which oxidises mercuric chloride to metallic mercury .

Options

A. If both the assertion and reason are true and reason is correct explanation of the assertion .
B. If both the assertion and reason are true but reason is not a correct explanation of the assertion .
C. If the assertion is true but the reason is false.
D. If both assertion and reason are false.

Answer

C

Explanation

`SnCl_(2)` ( stannous chloride ) on reaction with mercuric chloride `(HgCl_(2))`, oxidises to ` SnCl_(4)` (stannic chloride ) ` SnCl_(2)+2HgCl_(2) to SnCl_(4)+underset("(Greyish)")(Hg_(2)Cl_(2))`
So in this reaction, stannous chloride is acting as reducing agent that , reduces Hg(II) to Hg(I) and then to Hg(0)
`SnCl_(2)+Hg_(2)Cl_(2) to 2Hg +SnCl_(4)` .