# Question #b3e94

##### 1 Answer

#### Answer:

That actually depends on the mass / volume of the sample.

#### Explanation:

You know that your solution is

This type of percent concentration is calculated using the *mass of the solute*, which in your case is an acid, and the *volume of the solution*.

You will usually find it expressed in *grams per 100 mL*.

#color(blue)("%w/v" = "mass of solute"/"100 mL solution" xx 100)#

So, in essence, that **every**

For a given *volume* of solution, let's say

#V color(red)(cancel(color(black)("mL"))) * overbrace("62.02 g acid"/(100color(red)(cancel(color(black)("mL")))))^(color(purple)("%w/v")) = (62.02/100 * V)color(white)(a)"g acid"#

Now, if you are given the *mass* of the solution instead, let's say

#m color(red)(cancel(color(black)("g solution"))) * overbrace("1 mL solution"/(1.12color(red)(cancel(color(black)("g solution")))))^(color(purple)("density")) = (m/1.12) color(white)(a)"mL solution"#

Another interesting thing to do here is use the density of the solution to convert the concentration from *mass by volume* to *mass by mass*.

As you know, mass by mass percent concentration is defined as the mass of the solute divided by the mass of the solution, and multiplied by

#color(blue)("%w/w" = "mass of solute"/"mass of solution" xx 100)#

This means that you can write, using the given

#"62.02 g acid"/(100color(red)(cancel(color(black)("mL solution")))) * (1color(red)(cancel(color(black)("mL solution"))))/("1.12 g solution") = "62.02 g acid"/((100 * 1.12)"g solution")#

The percent concentration by mass will thus be

#"%w/w" = (62.02 color(red)(cancel(color(black)("g"))))/(112color(red)(cancel(color(black)("g")))) xx 100 = 55.375%#

In other words, **for every**