If you have 290.0 mL of water at 25.00 °C and add 120.0 mL of water at 95.00 °C, what is the final temperature of the mixture? Use 1.00 g/mL as the density of water.

Answer 1

heat gained by cool water + heat lost by warm water = 0
[mass cool water x specific heat x (Tfinal-Tinitial)] + [mass warm water x specific heat x (Tfinal-Tinitial)] = 0
Substitute and solve for Tfinal.

Answer 2

70