Question

5. Hot Al in Water

A large hot brick of Aluminum (m=2kg, T=630C) is placed in some water (m=0.75kg, 30C) to cool it. The system comes to equilibrium with no losses to the environment. What will be the final temperature and state of the two substances? (You can find the constants you need in the text on p.5) Part of this problem is to figure out if a phase change occurs or not. For full credit you must show how you did this

Answer 1

Heat lost be Aluminum = Heat gained by water

-(M c Delta) T Aluminium= (M C Delta T) water+ mLv (considering if aluminium is fully cooled to zero)

-2*921.096*(0-630) =0.75*4185.5 (100-30)+ 0.75*2258*1000

1160580.96= 219738.75+1693500

So heat lost by aluminium evenb it is fully cooled Heat released by it is enough to heat the water up to 100 degreee celcius,But not enough to fully convert water to vapour. So final temperature will stay at 100 degree celcius.

I have used the values from internet,You can check values given in your data booklet on page 5.