# Specific heat - calorimetry?

1. Apr 7, 2005

### Callisto

Specific heat - calorimetry??

Help from brainy chem person

How do determine the heat capacity of a calorimeter when,

You burn a 100mg of napthalene in it and it's temperature rises by 3.5 degrees C ?

the molar mass of napthalene is 128.18g/mol

Dont i need the specific heat of napthalene?

callisto

2. Apr 7, 2005

### Gokul43201

Staff Emeritus
No, you don't need the specific heat of naphthalene, because once you burn it, it's not naphthalene anymore.

Write and balance the reaction for the combustion of naphthalene. You can then either look up the heat of combustion (or get this from the calorific value of naphthalene) or you can calculate it from the various enthalpies of formation.

Then you can assume that this heat is absorbed entirely by the calorimeter.

3. Apr 8, 2005

### GCT

You should have been provided with specific instructions for this case.
The following may be the case

you'll probably deduce the heat lost in the reaction, through the calorimeter, that is not all of the heat of the reaction goes towards increasing the internal energy of the system. I'm not sure how the reaction was carried out, nevertheless the following reaction may apply

$$q_{reaction)=q_{air}+q_{cal}$$, q air corresponds to your measured temperature change, just an example.