1. Jan 17, 2010

### Dmitri10

"What is the specific heat capacity of a 50-gram piece of 100 degree C metal that will change 400 grams of 20 degrees C water to 22 degrees C?

Could someone please explain to me how to do this problem? I have to figure it out on my own because my teacher is no help at all.

2. Jan 17, 2010

### rock.freak667

The heat lost by the metal is equal to the heat gained by the water.

cwater=4.18 kJ/kgK

3. Jan 17, 2010

### Dmitri10

Okay, thank you. That leads me to another question, perhaps a silly one. How do I know when to use the 4.18 value instead of 1 cal/gC for water's specific heat capacity?

4. Jan 17, 2010

### Dmitri10

And... since the metal caused the water's temperature to increase by 2 degrees, does the metal's temperature decrease by 2 degrees?

5. Jan 17, 2010

### rock.freak667

it does not matter which one you use, you just need to be consistent with the units.

For example, if you just 4.18 kJ/kgK, you need mass to be in kg and temperature to be in K.

similarly for 1cal/gC, you need mass to be in grams (g) and temperature in C

6. Jan 17, 2010

### Dmitri10

Okay. That's what I presumed; that it didn't matter as long as units were consistent. Thank you for your help, though.

Hopefully my last question: is the change in temperature for the metal 2 degrees?

7. Jan 17, 2010

### rock.freak667

I think it should be that the metal and water would have the same final temperature.

8. Jan 17, 2010

### Dmitri10

Okay. I cannot believe I didn't realize that before I asked. Haha how embarrassing... anyway, thank you very much for your help.