# What is the weight/weight % of 9.74g of sodium sulfate to a final volume of 165 mL of solution?

##### 1 Answer

Here's what I got.

#### Explanation:

The problem here is that you're missing the density of the solution, which implies that you cannot use its volume to determine its mass.

The solution's **percent concentration by mass**,

You know that the solution contains

Now, let's say that this solution has a density of

In this case, the total mass of the solution will be

# 165 color(red)(cancel(color(black)("mL solution"))) * (rho quad "g")/(1color(red)(cancel(color(black)("mL solution")))) = (165 * rho) quad "g"#

So now that you know that you have

#100 color(red)(cancel(color(black)("g solution"))) * ("9.64 g Na"_2"SO"_4)/((165 * rho) color(red)(cancel(color(black)("g solution")))) = (5.84 * rho) quad "g Na"_2"SO"_4#

This means that the solution's percent concentration by mass is equal to

#"% m/m" = (5.84 * rho)% quad "Na"_2"SO"_4#

So if you find the density of the solution, you can plug in its value and get the solution's percent concentration by mass.