Question

Which has maximum number of molecules :-

• A. $7\,gm\,N_2$
• B. $2 \, gm \, H_2$
• C. $16 \, gm \, NO_2$
• D. $16 \, gm \, O_2$

Answer 1

Answer: (B)

$2 \, gm \, H_2$

Answer 2

In 7 g nitrogen, number of molecules $= \frac {7.0} {28} mol$
$= 0.25 \times N_A$ molecules
where, $N_A = \, Avogadro \, number \, = 6.023 \times 10^{23}$
In 2 g of $H_2 = \frac {2.0}{2} mol \, = 1 \times N_A$ molecules
In 16 g of , $NO_2 = \frac {16.0} {46} mol$
$\, \, \, \, \, \, \, \, = 0.348 \times N_A$ molecules
In $16\, g$ of $O_2 = \frac {16}{32} \, mol \, = 0.5 \times N_A$ molecules
Hence, maximum number of molecules are present in $2\, g$ of $H_2$.