## 8.99

Angela 1K
Posts: 80
Joined: Fri Sep 29, 2017 7:05 am

### 8.99

The question asks to find the final temperature of a solution when a piece of zinc of mass 8.5g is dropped into an apparatus containing 800.0mL of 0.500M HCl(aq). You're supposed to assume that the density and molar heat capacity of the HCl solution are the same as those of water. When looking at the solutions manual, they solve this equation using
$-20000J = (-4.184\frac{J}{g*C})(800g)(\Delta T)$
I don't understand why they used a negative heat capacity.

Thanks!

Michaela Capps 1l
Posts: 50
Joined: Thu Jul 27, 2017 3:00 am

### Re: 8.99

This is the idea that in a perfect system q(metal)+q(water)=0 so making overall q(water) negative, will be equal to q(metal).

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