Correct pair of compounds which gives blue colouration/precipitate and white precipitate, respectively, when their Lassaigne's test is separately done is

Options

A. `NH_(2)NH_(2).HCl and ClCH_(2)COOH`
B. `NH_(2)CSNH_(2) and PhCH_(2)Cl`
C. `NH_(2)CH_(2)COOH and NH_(2)CONH_(2)`
D.

Answer

D

Explanation

`NH_(2)NH_(2).HCl` does not contain C and hence does not give blue colour in Lassaigne.s test. `NH_(2)CSNH_(2)` contains both N and S and hence gives red colour in Lassaigne.s test. `NH_(2)CONH_(2)` does not contain Cl and hence does not give white ppt. Thus, `C_(6)H_(5)NHMe` contains N and hence gives blue colour while `o-C_(6)H_(4)(Cl)COOH` contains Cl and thus gives white ppt. in Lassaigne.s test.