Question

34 gm of $H_{2}O$ is decomposed to form _______ gm of hydrogen and ____ gm of oxygen.

• A. 30 gm of oxygen and 4 gm of hydrogen
• B. 16 gm of oxygen and 18 gm of hydrogen
• C. 32 gm of oxygen and 2 grams of hydrogen
• D. 3.78 gm H₂ and 30.22 gm O_2.

Answer 1

The correct option is D

3.78 gm H₂ and 30.22 gm O_2.

${2H}_{2}O$ $\to$ ${2H}_2$ + $O_2$

2 mole 2 mole 1mole

36 gm 4gm 32 gm

2 mole of water weighs 36 gm.

2 mole of $H_2$ weighs 4 gm

1 mole of $O_2$ weighs 32 gm

36 gm $H_{2}O$ gives 4gm $H_2$ and 32 gm $O_2$.
So, 34 gm $H_{2}O$ gives $\frac{4\times 34}{36}$ gm $H_2$ and $\frac{32\times 34}{36}$ $O_2$.
So, 34 gm $H_{2}O$ gives 3.78 gm $H_2$ and 30.22 gm $O_2$.