Question

1 mole of a gaseous aliphatic compound $C_n{H}_{3m}$ is completely burnt in an excess of oxygen. The moles of $H_{2}O$ formed are:

• A. $m\text{mol}$
• B. $\frac{3m}{2}\text{mol}$
• C. $2\text{mol}$
• D. $3m\text{mol}$

Answer 1

The correct option is B $\frac{3m}{2}\text{mol}$

$C_n{H}_{3m}+O_2\to C{O}_2+\frac{3m}{2}{H}_{2}O$
Since all the $H$ goes in $H_{2}O$ we do not need to balance oxygen and carbon atoms, we can directly calculate.
1 mol of $C_n{H}_{3m}$ produces $\frac{3m}{2}$ mol of hydrogen gas.