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Moles in Chemistry

I'm not sure what i'm suppose to be finding out in this question

Calculate the number of moles in the following quantities of solution. Please give your answer to 3 significant figures:

a) 100cm^3 of 0.050 mol/dm^3 nitric acid
b) 20cm^3 of 0.100mol/dm^3 ammonium hydroxide

Reply 1

Chlorophile

Original post by Subhadra.A

The concentration tells you how many moles there are in each litre (dm3) of substance. Therefore, if we know we have x number of moles of something in a litre, to find out the number of moles there actually are, we multiply the number of litres by the number of moles per litre.

In this case, you're given the volumes in cm3, not dm3. There are 1000cm3 in a dm3. So convert the cm3 to dm3, and then multiply by the concentration!