Question

Assertion (A) . Sulphur present in an organic compound can be estimated quantitaively be Carius method.
Reason (R). Sulpur is separated easily from other atoms in the molecule and gets precipitated as light yellow solid.
A. Both A and R are correct and R is the correct explanation of A
B. Both A and R are correct but R is not the correct explanation of As
C. both A and R are not correct
D. A is not correct but R is correct

Answer 1

Correct Answer - C
Both A and R are correct but R is not the correct explanation of A.
S present in an organic compound can be estimated quantitatively by Carius method. In this method, a known weight of organic compound is heated with fuming `HNO_(3)`, S present in it gets converted into `H_(2)SO_(4)`. On adding `BaCl_(2), H_(2)SO_(4)` gets precipitated as `BaSO_(4)` which may be of light yellow or white in colour.
If light yellow colour is obtained, it means some impurities are present. It is then filtered, washed, purified and then dired and finally pure `BaSO_(4)` of white colour is obtained.