Question

When 5.0g of CaCl2 was dissolved in 50 ml of water in a coffee cup calorimeter, the temperature of the solution rose from 22.3C to 30.5C. What is the qsoultion in J and what is the qrxn in J?

What is the deltaH in kJ/mol of CaCl2 dissolved?

Answer 1

I assume 50 mL H2O weighs 50 g.

q = mass H2O x specific heat H2O x (Tfinal-Tinitial)

Then q/gram = q/5 and delta H = (q/5) x (molar mass CaCl2) and convert that to kJ.
Remember that if the T increases then the heat from the rxn is exothermic and that makes delta H negataive.