Question

In the following experiment, a coffee-cup calorimeter containing 100 mL of H20 is used. The initial temperature of the calorimeter is 23.0 C . If 3.60 g of CaCl2is added to the calorimeter, what will be the final temperature of the solution in the calorimeter? The heat of the change in enthalpy (H)soln solution of CaCl2 is -82.8kJ/mol.
The specific heat of H2O is 4.18 kJ/g or 75.24 kJ/mol

Answer 1

Change 3.60 g CaCl2 to moles; moles = grams/molar mass
(-82,800 J/mol x moles CaCl2) + [moles H2O x specific heat water(J/mol) x (Tfinal-Tinitial)] = 0
Check my thinking.

Answer 2

it isn't necessary to change the mass in grams to moles. the equation reads out q=s*m*(final temp - initial temp) where q is the change in enthalpy, s is specific heat, and m is mass.