Question

An organic compound contains $1.6\%$ of $O$ atom. $1$ molecule of the compound contains $2$ atoms of $O$. The molecular mass of the compound is:

• A. $2000\text{g/mol}$
• B. $900\text{g/mol}$
• C. $320\text{g/mol}$
• D. $960\text{g/mol}$

Answer 1

The correct option is A $2000\text{g/mol}$

Assuming $100\text{g}$ of the sample to be present,
$100\text{g}$ contains $1.6\text{g}$ of $O$.
Since the number of $O$ atom present in one molecule of compound to be two, the mass of $O$ present in $1$ mole of the substance is $32\text{g}$.

Molar mass of the substance $=\frac{100\times 32}{1.6}=2000\text{g/mol}$