Question

Study the following table

	Compound (mol. mass)	Mass of the compound (in gram) taken
$I.$	$CO_{2}\left(\right.44\left.\right)$	4.4
$II.$	$NO_{2}\left(\right.46\left.\right)$	2.3
$III.$	$H_{2}O_{2}\left(\right.34\left.\right)$	6.8
$IV.$	$SO_{2}\left(\right.64\left.\right)$	1.6

Which two compounds have least mass of oxygen?

• A. II and IV
• B. I and III
• C. I and II
• D. III and IV

Answer 1

Answer: (A)

Mass of oxygen present $=\frac{w t . o f C o m p o u n d}{M o l . w t . o f c o m p o u n d}\times 32$

I. Mass of oxygen present $=\frac{4.4}{44}\times 32=3.2g$

II. Mass of oxygen present $=\frac{2.3}{46}\times 32=1.6g$

III. Mass of oxygen present $=\frac{6.8}{34}\times 32=6.4g$

IV. Mass of oxygen present $=\frac{1.6}{64}\times 32=0.8g$

So II and IV have least mass of oxygen.