Question

Complete combustion of $1.80g$ of an oxygen containing compound $\left(C_x{H}_y{O}_z\right)$ gave $2.64g$ of $C{O}_2$ and $1.08g$ of $H_{2}O$. The percentage of oxygen in the organic compound is:

• A. 50.33
• B. 53.33
• C. 51.63
• D. 63.53

Answer 1

The correct option is B 53.33

$C_x{H}_y{O}_z+O_2\to xC{O}_2+\frac{y}{2}{H}_{2}O$

$2.64g\text{of}C{O}_2\text{contains}0.72gC$

$1.08g\text{of}{H}_{2}O\text{contains}0.12gH$

$\therefore \text{mass of oxygen present}=1.80-(0.72+0.12)=0.96g$

$\%O=\frac{0.96}{1.80}\times 100=53.33\%$