Question

What is the volume of solution with 0.82g/L concentration when the mass of the solute is 7g?

Answer 1

`"9 L"`

Explanation:

The idea here is that the concentration of the solution tells you the number of grams of solute present for every `"1 L"` of the solution.

This solution is said to have a concentration of `"0.82 g L"^(-1)`, which means that `"1 L"` of this solution will contain `"0.82 g"` of solute.

Now, you know that you have a sample of this solution that contains `"7 g"` of solute. As you know, a solution is a homogeneous mixture, which implies that it has the same composition throughout.

Consequently, you can use the concentration of the solution to determine how many liters would contain `"7 g"` of solute.

`7 color(red)(cancel(color(black)("g solute"))) * overbrace("1 L solution"/(0.82color(red)(cancel(color(black)("g solute")))))^(color(blue)("= 0.82 g L"^(-1))) = color(darkgreen)(ul(color(black)("9 L solution")))`

The answer is rounded to one significant figure, the number of sig figs you have for the mass of the solute.