# What is mass percentage of benzene $(C_6H_6)$ in carbon tetrachloride $(CCl_4)$ if 20g of benzene is dissolved in 180g of $CCl_4$?

$\begin{array}{1 1}(a)\;10\%\\(b)\;9\%\\(c)\;2\%\\(d)\;8\%\end{array}$

Mass percentage $= \large\frac{\text{mass of benzene}}{\text{mass of solution}}$$\times 100\% Mass of Benzene = 20g, Total mass of the solution = 20 + 180 = 200g. \Rightarrow Mass percentage = \large\frac{20}{200} \%$$= 10\%$
edited Jul 16, 2014