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