Q. The sodium extract of an organic compound on acidification with acetic acid and addition of lead acetate solution gives a black precipitate. The organic compound contains
A) Nitrogen
B) Halogen
C) Sulphur
D) Phosphorus
Explanation
(c)
The organic compounds is fused with Na metal, $Na_{2}S$ is formed which is tested as
It reacts with lead acetate and forms black ppt. of $PbS$
$Na_{2}S + \left( CH_{3}COO \right)_{2}Pb \rightarrow PbS\ + 2CH_{3}COONa$
$\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ black\ ppt$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.