Question

Which of the following contain maximum number of molecules?

• A. 1g $C{O}_2$
• B. 1g $N_2$
• C. 1g $H_2$
• D. 1g $C{H}_4$

Answer 1

The correct option is C 1g $H_2$

For a molecule,

molecular weight in grams $=$ Avogadro's number$\left(N_A\right)=6.023\times {10}^{23}$
(A) 1g $C{O}_2$

44 gram of ${CO}_2$ =$N_A$ molecules
$\therefore$ 1 gram of $C{O}_2$ contains $\frac{1}{44}\times N_A$ molecules
(B) 1g $N_2$
28 gram of $N_2=N_A$ molecules
$\therefore$1 gram of $N_2$ contains $\frac{1}{28}\times N_A$ molecules
(C) 1g $H_2$

2 gram of $H_2$ contains $N_A$molecules

$\therefore$ 1 gram of $H_2$ contains $\frac{1}{2}\times N_A$ molecules
(D) 1g ${CH}_4$
16 gram of ${CH}_4$ =$N_A$ molecules
$\therefore$ 1 gram of ${CH}_4$ =$N_A/16$

Maximum number of molecules are found in 1 gram hydrogen.