Chemistry Question

Im doing quesitions about Concentration, i understand them but dont understand what is the concentration what is the moles but i know the volume is the one with cm3

What is the concentration units it moles per dm3
or is it mol/dm3

what is the units for moles

thanks for any replies

Unit for moles is mol.
Unit for volume is dm^3.

Equation for concentration is... Concentration = moles / volume

Therefore the unit for concentration is mol / dm^3.

If the volume you use is in cm^3, then the concentration calculated will be in mol / cm^3.

But it helps to convert all values to the SI units before calculating, so divide any cm^3 by 1000 to get that value in dm^3 - then go from there.

Regardless of whether you are using dm^3 or cm^3, you are still in SI units the "d" and "c" parts are simply orders of magnitude. Whether you should divide by 1000 first depends totally on what the question asks. Edexcel exams in general use mols/dm^3, but I've seen some weird and wonderful things.