Question

Hydrogen and oxygen combine in the ratio of $1:8$ by mass to form water. What mass of oxygen gas would be required to react completely with $3g$ of hydrogen gas?

• A. $12\text{g}$
• B. $24\text{g}$
• C. $8\text{g}$
• D. $3\text{g}$

Answer 1

The correct option is B $24\text{g}$

Given,
Hydrogen and oxygen combine in the ratio of $1:8$ by mass to form water
Therefore,
Mass of oxygen gas required to react completely with $1\text{g}$ of hydrogen gas is $8\text{g}$
Therefore,
The mass of oxygen gas required to react completely with $3g$ of hydrogen gas $=8\times 3=24g$.