Question

How much grams of methane contains as many hydrogen atoms as there are in 4 grams of hydrogen gas.

• A. $8gm$
• B. $4gm$
• C. $32gm$
• D. $16gm$

Answer 1

The correct option is D $16gm$

Since 2 grams of $H_2$ has $2\times N_A$ number of atoms = $12.046\times {10}^{23}$
So 4 gm of hydrogen gas will have $24.092\times {10}^{23}$ atoms of hydrogen
Also 1 mole of methane contains $4\times N_A=24.092\times {10}^{23}$ atoms of hydrogen
Therefore the amount of methane gas required = 1 mole of methane gas = molecular weight of methane = 16 gm

Hence, the correct option is $\text{D}$