Which of these gases can be dried with concentrated H2SO4?

A.

HBr

B.

H2S

C.

NH3

D.

SO2

Correct answer is D

In the preparation of \(SO_{2}\), we have the resultant reaction from heating the mixture of \(Na_{2}SO_{3}\) and \(HCl\) as:

\(Na_{2}SO_{{3}{(aq)}} + 2HCl_{(aq)} \to 2NaCl_{(aq)} + H_{2}O_{(l)} + SO_{{2}{(g)}}\)

Passing the gas evolved through conc. \(H_{2}SO_{4}\), we collect \(SO_{2}\) by DOWNWARD DELIVERY, leaving \(NaCl\) in the flask.