# Question a4c01

May 5, 2017

$1.7 \cdot {10}^{3} \text{ppm}$

#### Explanation:

The thing to remember about a mixture's concentration in parts per million, or ppm, is that it is supposed to tell you the number of parts of a given component of the mixture present for every

${10}^{6} = 1 , 000 , 000$

parts of mixture. In your case, you know that the sample has a total mass of $\text{70 g}$. This sample is said to contain $\text{0.119 g}$ of iron.

Your goal here is to figure out how many grams of iron you would get for ${10}^{6}$ $\text{g}$ of sample by using its known composition.

10^6 color(red)(cancel(color(black)("g sample"))) * "0.119 g Fe"/(70color(red)(cancel(color(black)("g sample")))) = 1.7 * 10^3# $\text{g Fe}$

This means that the sample's concentration in parts per million is equal to

$\textcolor{\mathrm{da} r k g r e e n}{\underline{\textcolor{b l a c k}{\text{concentration Fe" = 1.7 * 10^3color(white)(.)"ppm}}}}$

I'll leave the answer rounded to two sig figs, but keep in mind that you only have one significant figure for the mass of the sample.