# Homework Help: Calculate concentration

1. Oct 6, 2008

### briteliner

1. The problem statement, all variables and given/known data

given a 10.0mL sample of Ba(OH)2 solution, calculate the concentration of the solution if it took 7.85mL of a .102 M H2SO4 to reach the equivalence point
2. Relevant equations

3. The attempt at a solution

2. Oct 7, 2008

### Staff: Mentor

You just don't ask. You try, you tell us what you did, we push you in the right direction.

3. Oct 12, 2008

### Tamoki

I'm going to assume you have no clue how to start this problem, seeing as you did not attempt it.

Because both compounds have an equal number of Hydroxides/Hydrogens the normalities would be the same, nevertheless I'll go through normality just to show you.

Normality(N) = Moles on Hydroxide/Hydrogen(n) * Molarity(M)

So the H2SO4 solution is .204 N.

The neutralization equation is N1V1 = N2V2

So, (.204 N) * (.00785 L) = (X N) * (.0100 L)

Find X, then divide it by 2 to get Molarity.

OR...

You can just go through moles because they have the same Normality.

Molarity(M) = Moles(n)/Volume(L)

Take your Molarity and multiply it by your volume. That gives you moles so you can set up another Molarity equation.

Good luck, now you should have all the tools you need!