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chemistry titration question (a level)

Hi, does anyone know how to do 6.1 on this paper. I get that you need to work out the mass of copper than you should add and that is should be less than 0.005 moles, then convert this to grams. However, after this I am not sure what to do or why? I don't really understand how titrating the excess hcl allows you to work out the Mr? Also, how do you know the volume and concentration of NaOH to titrate it against? thanks

https://filestore.aqa.org.uk/resources/chemistry/AQA-74041-SQP.PDF

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Correct me if I’m wrong... but here’s my thought:
1. Weight the given Calcium Hydroxide solid to obtain the total weight of the thing
2. Add an excess but known no. of mol of HCl with the solid and make sure all the Calcium Hydroxide solid has reacted with HCl that there should not be any solid in the mixture.
3. In the mixture, apart from the reaction product, there would be unreacted HCl (as it was added in excess)
4. The unreacted HCl in the mixture would be able to carry out titration with standard sodium hydroxide so that the molarity of the HCl in the mixture can be known.
5. Through calculations... the no. of moles of unreacted HCl in the mixture should be found
6. By using the unreacted no. of mol to minus the total original no. of mol of HCl added in the beginning, the reacted no. of mol can be obtained
7. The reacted no. of Calcium Hydroxide can therefore be obtained
8. The weight can be divided by the no. of mol and the result is obtained :smile: