If 100.0 g of water at 90 deg. C is added to 50.0 g of water at 10 deg. C, estimate the final temperature of the water.

When mixing substances, in order to find the final temperature after mixing, it is important to remember that the energy released should be equal to the energy absorbed by the system. We calculate as follows:

Q1 = Q2

(mCΔT) 1 = (mCΔT) 2

100 (90 - T) = 50 (T - 10)

T = 63.33 °C