# Question #82dbf

##### 2 Answers

#### Explanation:

**Parts per million**, or **ppm**, is simply another way of expression the concentration of a solution.

More specifically, parts per million can be used for solutions that contain very, very small amounts, often called *trace amounts*, of solutes.

By definition, ppm concentration is expressed as

#color(blue)(|bar(ul(color(white)(a/)"ppm" = "grams of solute"/"grams of solvent" xx 10^6color(white)(a/a)|)))#

In essence, a concentration of **for every**

#"1 ppm" = (1color(red)(cancel(color(black)("g"))) "solute")/(color(brown)(cancel(color(black)(10^6)))color(red)(cancel(color(black)("g")))"solvent") xx color(brown)(cancel(color(black)(10^6)))#

In your case, the solution is said to have a concentration of **for every**

Notice that if you were to pick a sample of *solvent* and add *solute*, you can approximate the mass of the **resulting solution** as

#"73.2 g solute " + color(white)(a)10^6"g solvent" ~~ 10^6"g solution"#

Now, to get the solution's **percent concentration by mass** (or weight percent), **for every**

#color(blue)(|bar(ul(color(white)(a/a)"% m/m" = "grams of solute"/"grams of solution" xx 10^2color(white)(a/a)|)))#

Since we've picked a sample that contains **percent concentration by mass** will be

#"% m/m" = (73.2 color(red)(cancel(color(black)("g"))))/(10^6color(red)(cancel(color(black)("g")))) xx 10^2 = color(green)(|bar(ul(color(white)(a/a)"0.00732%"color(white)(a/a)|)))#

So, instead of saying that your solution is **by mass**, you would say that it's

Ppm stands for "parts per million".

#### Explanation:

In other words, "How many grams are in one million grams of the sample?"

In the same way, mass percent is the number of grams in 100 g of the sample.

For example,

We want to know the mass of the component in