Calculate mass of aluminum cup

Question

An aluminum cup contains 225 g of water and a 40-g copper stirrer, all at 27°C. A 438-g sample of silver at an initial temperature of 89°C is placed in the water. The stirrer is used to stir the mixture gently until it reaches its final equilibrium temperature of 32°C. Calculate the mass of the aluminum cup.

g

Answer 1

One needs to know the specific heat for aluminum, copper, silver and water.  Water has a value of 4.184 J/g/deg, but I'd have to look up the others (which you can also do).

(mass Al cup)(sp.heat A) (32-27) + (225g)(4.184)(32-27) + (40g)(sp.heat Cu)(32-47) = (438)(sp.heat Ag)(89-32)

Solve for mass of Al cup