# A solution of HCl in water has a density of 1.1 g/mL. What is the mass% of HCl in the solution if 150 mL of the solution contains 30. g of HCl?

##### 1 Answer

#### Explanation:

The first thing that you need to do here is to use the **density** of the solution to determine the mass of

The density of the solution is said to be equal to **every**

This means that your sample will have a mass of

#150 color(red)(cancel(color(black)("mL"))) * "1.1 g"/(1color(red)(cancel(color(black)("mL")))) = "165 g"#

Now, in order to find the solution's **percent concentration by mass**,

Since you know that

#100 color(red)(cancel(color(black)("g solution"))) * "30. g HCl"/(165color(red)(cancel(color(black)("g solution")))) = "18.18 g HCl"#

You can thus say that the solution has a percent concentration by mass equal to

#color(darkgreen)(ul(color(black)("% m/m = 18% HCl")))#

The answer is rounded to two **sig figs**.