## Textbook Problem 8.21

Vandan_Patel_3L
Posts: 14
Joined: Wed Sep 21, 2016 2:55 pm

### Textbook Problem 8.21

I was wondering how to start this problem and if I do two separate equations for water and copper.

A piece of copper of mass 20.0 g at 100.0 C is placed in a vessel of negligible heat capacity but containing 50.7 g of water at 22.0 C. Calculate the final temperature of the water. Assume that no energy is lost to the surroundings.

Rachel Kipp 1I
Posts: 16
Joined: Wed Sep 21, 2016 2:55 pm

### Re: Textbook Problem 8.21

Keep in mind that q(system)+q(surroundings) = q(universe), which = 0

So, the heat lost by the metal = - heat gained by the water

You can use q=mC(s)(T(final) - T(initial)) in place of the metal and the water, as seen with the set up of the equation above. Plug in the information given, then you will have to solve for T(final)

Daniel Dobrin 2F
Posts: 12
Joined: Sat Jul 09, 2016 3:00 am

### Re: Textbook Problem 8.21

What you do is you set nC(Tf-Ti)=-nC(Tf-Ti). Now just be consistent with the grams and heat capacity copper and water by making sure they're on the same side of the equation. I personally did copper on the left side and water on the right (negative) side.