Question

1. Solution 'A' gives black ppt, with dil. HCl and H2S gas, which basic radical is
present in given solution.
Doceribe identification nrocadura af R22+ or Ca2+ radical from given unknown​

Answer 1

The Basic radical present in the Solution is Ag+.

Here the solution used is AgNO3.

The identification procedure of Calcium cation is:

• Take a soluble salt of Calcium such as Ca(No3)2 and combine it with oxalic acid.
• on reacting we get a  precipitate calcium oxalate (CaC2O4).
• this precipitate can easily react with acid such as H2SO4.
• on reaction with the acid, we get a white precipitate CaSO4.
• Hence, Ca2+ radical is identified.

Ca(NO3)2 + H2C2O4 = CaC2O4 + 2 HNO3

CaC2O4 + H2SO4 = CaSO4 + H2C2O4