# Heat Capacity iron heating water

1. Jan 12, 2005

### bjorn

This is what I've got:

Iron mass: 81.9g
Initial iron temp.: 92'C
Water volume: 100mL
Initial water temp.: 25'C
Final water temp.: 29'C

What the the experimental heat capacity of iron?

Thanks :)

Bjorn

2. Jan 12, 2005

### Gokul43201

Staff Emeritus
Bjorn, do you know what equation is to be used for this kind of problem. It's very simple and will be in your textbook. Look it up.

We can not do your homework for you. You have to make an attempt first.

3. Jan 12, 2005

### bjorn

Hmmm...

mm = 81.9g

mw = 100mL

Tim = 92°C

Tf = 29°C

Tiw = 25°C

Tfw = 29°C

cw = 4.19 J/g·°C (this is the number the school operates with)

cm = ?

81.9g(cm)(29°C - 92°C)+100g(4.19J/g·°C)(29°C - 25°C) = 0

81.9g(cm)(-63°C)+100g(4.19J/g·°C)(4°C) = 0

-5159.7g·°C(cm)+1676J = 0

1676J = 5159.7g·°C(cm)

Divide both sides by 5159.7g·°C:

cm = 0.325J/g·°C

Didn't take this from the text book, I guess I knew what to do, but I have always been an idiot with unkowns in math :rofl:
Equations and me aren't exactly best friends.

4. Jan 12, 2005

### Gokul43201

Staff Emeritus
This is perfectly good.

Aren't you glad you did it by yourself, rather than have someone else do it for you ?