Question

19. A gaseous mixture contains oxygen and nitrogen
in the ratio of 1:4 by weight. Therefore the ratio
of their number of molecules is
(a) 1:4
(b) 1:8
(c) 7:32
(d) 3:16​

Answer 1

Ratio of O2 : N2 by weight=1:4.

Let the weight of O2= 1 gm.

The weight of N2=4 gm.

The ratio of the No. Of molecules will be the ratio of the Number of their moles ie.,

= 1/32 :4/28

= 28: (4 x32) = 7 : 32

= 7:32 .

hope it helps