Q. In qualitative analysis, in order to detect second group basic redical, $H_{2}S$ gas is passed in the presence of dilute $HCl$ to
A) Increase the dissociation of $H_{2}S$
B) Decrease the dissociation of salt solution
C) Decrease the dissociation of $H_{2}S$
D) Increase the dissociation of salt solution
Explanation
(c)
In qualitative analysis, in order to detect IInd group radicals, $H_{2}S$ gas is passed in the presence of dilute $HCl$ to decrease the dissociation of $H_{2}S$ by common-ion effect so that less $S^{2 -}$ions are obtained and only IInd group radical could precipitate.
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.