Question

A sample of drinking water was found to be severely contaminated with $CC{l}_4$, which is supposed to be carcinogenic in nature. The level of contamination was 15 ppm (by mass). Calculate the mass percentage of $CC{l}_4$.

• A. $1.5\times {10}^{-3}\%$
• B. $1.5\times {10}^{-4}\%$
• C. $0.005\%$
• D. $0.001\%$

Answer 1

The correct option is A $1.5\times {10}^{-3}\%$

We know that:
$partpermillion=\frac{massofsolute}{massofsolution}\times {10}^6$
$\frac{massofsolute}{massofsolution}=\left(partspermillion\right)\times {10}^{-6}$
$masspercentage=\frac{massofsolute}{\left(massofsolution\right)}\times {10}^2$
$Masspercentage=\left(partspermillion\right)/{10}^4=1.5\times {10}^{-3}\%$