[ihatemunichs]

Hi there

i need help on a little  part of the section.

The pecentage purity of an acid..

the three questions are  
1 average titre,and molarity of acid
2 using calculated molarity determine conc of acid in g/m3
3 calc %age purity

i have worked part1 no problem but what does conc in g/m3 mean?i thought molarity was concentration.and how does that lead me to %age purity?

the key details are as follows

solid monoprotic acid mr 163.caculate ppurity with titration with naoh? (25cm3 portions of0.150 M NaOh)
7.1g of the acid was used,dissolved in water and made upto 250cm3.
the average titre was 22.25 and the molarity was 0.169 as asked in part 1...so how do i work out the rest??



thanks for your help..

[Borek]

2 using calculated molarity determine conc of acid in g/m3
3 calc %age purity

I doubt these points are related, g/m3 is one of the numerous ways of expressing concentration (and a silly one to say the truth, as it is almost the same as % w/v - you may check concentration follies in the CASC help if you want to know my opinion).

You know molar mass, you know molar concentration from titration - just calculate how much acid (mass) was in the sample, divide by sample mass and that'll give you % purity.