Question

A gaseous mixture contains oxygen and nitrogen in the ratio of 1:4 by weight. Therefore, the ratio of their number of molecules is

(IIT-JEE, 1979)

• A. 1:4
• B. 1:8
• C. 7:32
• D. 3:16

Answer 1

The correct option is C 7:32

	$O_2$	$N_2$
Weight ratio	1	4
Moles ratio	$\frac{1}{32}$	$\frac{4}{28}=\frac{1}{7}$
Molecules ratio	$\frac{1}{32}N$	$\frac{1}{7}N$
Molecules ratio	7	32