Let's look at an example to see how we can use this equation.

So we have C1V1 = C2V2.

There are some words I have to look for to see if this is in fact a dilution problem.

The most obvious is diluted, or dilution.

We can talk about the addition of solvent.

We can talk about the amount of solute staying same, but

the volume of the solution changing.

And these are all key words to clue us in that this is a dilution problem.

The other thing we notice is that there's only one substance listed.

Here, we only mention NaOH.

We don't talk about anything else present which it could react with.

So what I want to do is sort my information and

group it together correctly.

I see that a solution was 1.45 liters of .875 molar NaOH.

So that tells me that these two numbers actually belong together.

So I'm gonna call them C1 and V1.

Then I said it was diluted to a new volume up to 2.25 L,

what is the new concentration?

So I'm gonna call this V2, and what we're gonna actually be solving for

is C2 with that unknown concentration.

So, I can plug my numbers in, 0.875 molar NaOH,

for C1 times 1.45 L equals concentration 2 or

C2, which I don't know,

times the volume, 2.25 liters.

Now I can simply do the calculation to solve 4 the concentration

2 which is the concentration of the dilute solution.

What I find is that I get 0.564 molar.

I know it's going to be in units of molarity because my concentration 1 was in

units of molarity and they must be the same.

When I look at this I also see that my answer is reasonable.

When we have a dilution happening, the more dilute solution is always going

to have a lower concentration than the original concentrated solution.