Need help quick - Calorimetry?

Question

A 0.10 kg piece of copper at an initial temperature of 95°C is dropped into 0.20 kg of water contained in a 0.28 kg aluminum calorimeter. The water and calorimeter are initially at 15°C.
What is the final temperature of the system when it reaches equilibrium?


Thanks everyone!

Answer 1

We will consider this a perfectly insulated system...

Basically the sum of heat changes should be = 0

mw = mass of the water
cw = specific heat of water
mc = mass of the copper
cc = specific heat of copper

0 = mc*cc*(Tf-95) + mw*cw*(Tf - 15)

Now we have to solve for Tf

mc*cc*Tf - 95*mc*cc + mw*cw*Tf - 15*mw*cw = 0

Tf = (95*mc*cc + 15*mw*cw )/(mc*cc + mw*cw)

I don't know the specific numbers for cc and cw, but you should have those. Remember that if cc and cw are in units of K that the temps should also be in K.

Good luck.