Chemistry Final Temp

Question

A 356.6 g piece of gold (Cp=25.42 J/mol °C) was heated to a temperature of -23.4 °C and then placed in contact with a 1057 g piece of uranium at 78.2 °C (Cp=27.67 J/mol °C). What is the final temperature of the two pieces of metal in degrees C? Assume no heat is lost into the environment. Show your work.

Answer 1

Heat lost by the hot metal = heat gained by the colder metal

heat = q = mC∆T where m = mass; C = specific heat; ∆T = change in temperature

moles uranium = 1057 g x 1 mol/238 g = 4.441 moles

moles gold = 356.6 g x 1 mol/197 g = 1.810 moles

(4.441)(27.67)(78.2 - Tf) = 1.810)(25.42)(Tf - -23.4)

9609 - 122.88Tf = 46.01Tf + 1077

168.89Tf = 8532

Tf = 50.5ºC