# How many grams of solute are in #"2.5 L"# of a solution which is #"20% w/v"# ?

##### 1 Answer

#### Explanation:

A solution's **mass by volume percent concentration**,

So if you take exactly

In your case, the solution is **for every**

#color(blue)(20)color(red)(%)"m/v" " " implies " " color(blue)("20 g") color(white)(.)"solute in"color(white)(.)color(red)("100 mL")color(white)(.)"of solution"#

You can thus say that your sample contains

#2.5 color(red)(cancel(color(black)("L solution"))) * (10^3color(red)(cancel(color(black)("mL"))))/(1color(red)(cancel(color(black)("L")))) * "20 g solute"/(100color(red)(cancel(color(black)("mL solution")))) = color(darkgreen)(ul(color(black)("500 g solute")))#

The answer is rounded to one **significant figure**, the number of sig figs you have for the solution's mass by volume percent concentration.