[mass]

When I use to work out number of moles I did cv/1000. If the concentration was in cm3, I had to divide by 1000 and if it was in dm3 I didn't.

What I don't get is, I hav a question here which is number of moles for a 25ml of a 0.25m solurion. Now for this wouldnt I still have to divide by 1000 as the volume is in ml except the worked example isnt. Ml is cm3 right?

[sjb]

ml is the same as cm³, yes (at least, these days they're the same, but that's a different story), but Ml is not.

See e.g. http://www.google.com/search?q=1+ml+in+cm%5E3, and http://en.wikipedia.org/w/index.php?title=SI_prefix&oldid=203597883.

Also, I'm not 100% sure what you mean by "25ml of a 0.25m solution". It's probable, given what you have already written that you mean 0.25M. Be careful however, as m is also used as a measure of concentration (molality), in the latter case you will also need the density of the solution (http://en.wikipedia.org/w/index.php?title=Concentration&oldid=204023891).

edit rephrase ambiguities

[mass]

ml is the same as cm³, yes, but Ml is not (at least, these days they're the same, but that's a different story).

See e.g. http://www.google.com/search?q=1+ml+in+cm%5E3, and http://en.wikipedia.org/w/index.php?title=SI_prefix&oldid=203597883.

Also, I'm not 100% sure what you mean by "25ml of a 0.25m solution". It's probable, given what you have already written that you mean 0.25M. Be careful however, as m is also used as a measure of concentration (molality), in the latter case you will also need the density of the solution (http://en.wikipedia.org/w/index.php?title=Concentration&oldid=204023891).

Yes I mean a M, so number of moles can be calculated. You haven't answered my question, just repeated that ml is same as cm3 which I said anyway.

[sjb]

Yes I mean a M, so number of moles can be calculated. You haven't answered my question, just repeated that ml is same as cm³ which I said anyway.

Fair point. The only question I saw in your original post was

... ml is cm³ right?

so I was just agreeing with you.  So you have c, and a measure of v/1000, so you can work out the number of moles as you require.