moles to mL?

[scavok]

I've been trying to figure this problem out for atleast an hour, I just don't understand how to get the volume. I can't find any examples of such problems in my textbooks, only problems to get the mass, not volume.

Here's the question verbatim:

What volume (mL) of 6.0M H2SO4 should be taken in order to prepare 50.0 mL of a solution which is 0.25M in H2SO4?


The molecular weight of H2SO4 is 98.078amu (g/mol)

I don't really even know where to go from there. I guess you would need the amount of grams in .25M of H2SO4, which is 24.520g. But how the heck do you get volume? You would need the density, wouldn't you?

Maybe if someone could just rewrite the question using different terms I would understand it. It doesn't even seem like it's written in english to me. Particularly the "which is 0.25M in H2SO4" part.

Thanks for the help

[cepheid]

It looks like you're having a problem with terminology here. The problem does give you all of the information you need to solve it. It can be easily translated into english ( :wink: ) from the fairly commonplace chemistry shorthand used to indicate solution concentrations. 6.0M H2SO4 should be read as "six molar sulfuric acid". What is this "molar"? It is a unit for concentration, a shorthand for moles per litre!!! Now the problem should make sense, as you have been given the initial and desired final solution concentrations.

[thunderfvck]

c1v1 = c2v2

c1: initial concentration
c2: final concentration
v1: initial volume
v2: final volume

Keep your units consistent.

[chem_tr]

As an addition to the friends posted, molarity times volume gives millimoles if M and mL are used, respectively. You'll get moles if M and L are used (resp.). I think it would be better to quote this:

molarity=\frac{moles}{liters} or \frac{millimoles}{milliliters}