[shady145]

u'll probably have to use (delta)H=-mc(delta)t
have u come across this eq yet?
with the molar heat of solution, when ur testing different substances measure the mass u use. eg. if u use salt solution, then weigh the amount of salt u put in. this will allow u to work out moles.
so
1. put 100ml water in beaker, record start temp (distilled water, so dnt get it out of the tap like aimed92 said) heat for 10 minutes or so using a bunsen burner. record the max temperature reached in the time, also record the temp every minute.
2. add say 10g of salt to 100ml distilled water, record start temp, heat for 10 minutes and record temp every minute.
3. use the equation (delta)H=-mc(delta)t to work out (delta)H for both steps 1&2, which is the heat energy.
4. calculate the amount of moles of salt used. u c how to finish it? if not ask me