Chemistry - Mole Concept Question with Solution | TestHub

Let the mass of one atom of element 'x' be $m_x$ and the mass of one carbon atom be $m_C$.

Given that the ratio of the mass of an atom of element 'x' to the mass of a carbon atom is $9:1$, we have:

$\frac{m_x}{m_C}=\frac{9}{1}$

The ratio of their molar masses is equal to the ratio of their atomic masses:

$\frac{M_x}{M_C}=9$

Given the molar mass of carbon, $M_C=12\text{g/mol}$, the molar mass of element 'x' is:

$M_x=9\times 12=108\text{g/mol}$

Therefore, the mass of $1\text{mol}$ of element 'x' is $108\text{g}$.