Question

Arrange the following in the order of their increasing masses.
(Atomic mass : $O =16, N =14$ )
I. One atom of oxygen
II. One atom of nitrogen
III. $1 \times 10^{-10}$ mole of oxygen

• A. II < I < III
• B. I < II < III
• C. III < II < I
• D. II < III < I

Answer 1

Answer: (A)

I. Mass of one atom of oxygen
$= \frac{16}{6.023\times10^{23}} = 2.66 \times10^{-23} g$
II. Mass of one atom of nitrogen
$= \frac{14}{6.023\times10^{23}} = 2.32 \times10^{-23} g$
III. Mass of $1 \times 10^{-10}$ mole of oxygen
$= 16 \times 10^{-10} g$
So, the order of increasing masses is $II < I < III$.