Suppose you store a 15.5 g piece of aluminum (Cp of Al = 0.902 J/g⁰C) in the refrigerator at 2.3⁰C and then drop it into your coffee. The coffee temperature drops from 95.6⁰C to 45.6⁰C. How many Joules of energy did the aluminum block absorb?

605.4 J

Explanation:

When a certain substance absorbs a certain amount of energy, its temperature increases according to  the equation:

where

Q is the heat absorbed

m is the mass of the substance

C is the specific heat capacity of the substance

is the change in temperature

In this problem, we have:

m = 15.5 g is the mass of the piece of aluminium

C = 0.902 J/g⁰C is the specific heat of the aluminium

is the change in temperature of the aluminium (in fact, at thermal equilibrium, the block of aluminium reaches the same final temperature as the coffee)

Therefore, the energy absorbed is