# After performing a dilution calculation, you determine you need 25.0 milliliters of an aqueous stock solution to make 100.0 milliliters of a new solution. How would this be prepared?

##### 1 Answer

Here's what I got.

#### Explanation:

You know that you need

#(100.0color(red)(cancel(color(black)("mL"))))/(25.0color(red)(cancel(color(black)("mL")))) = 4#

You thus know that **for every** **parts** of this new, diluted solution, **part** is accounted for by the stock solution and **parts** are accounted for by water, you *diluent*.

The trick now is to realize that despite the fact that you'd need

#"100.0 mL " - " 25.0 mL" = "75.0 mL"#

of water to make this new solution, you **should not** add exactly *enough water* to make sure that the **total volume** of the solution is equal to

So, to prepare this solution, you should add