Year 12s: what will be the first way you research your future options? >>

Double salt questions! AS

Hi everyone,

I have to do some questions about a double-salt preparation that we did and was wondering if someone could help me with a few of the questions. Rep will be given to anyone that helps.

Method:

Make one of the salts
Make the other salt
Mix them together
Boil some of the liquid off
Leave to crystallize

Firstly, why is the volume of the solution reduced? i.e. why is some of the liquid boiled off?

Also, when we were making one of the salts (ammonium sulfate solution) why did I have to keep on adding ammonia until red litmus turned red?

Finally, when calculating moles, do you include the water of crystallization in your calculations?

Thanks guys!