Question

Which one of the following has minimum number of molecules?

• A. $10g{H}_2$
• B. $88gC{O}_2$
• C. $51gN{H}_3$
• D. $18g{H}_{2}O$

Answer 1

The correct option is D $18g{H}_{2}O$

$H_2:\text{number of molecules}=\frac{10}{2}\times N_A=5N_A$
$C{O}_2:\text{number of molecules}=\frac{88}{44}\times N_A=2N_A$
$N{H}_3:\text{number of molecules}=\frac{51}{17}\times N_A=3N_A$
$H_{2}O:\text{number of molecules}=\frac{18}{18}\times N_A=N_A$