August 06, 2024, 02:51:12 AM
Forum Rules: Read This Before Posting

### Topic: Calculate energy of combustion of fuels  (Read 10081 times)

0 Members and 1 Guest are viewing this topic.

#### Blah DTMM

• Regular Member
• Posts: 13
• Mole Snacks: +0/-0
##### Calculate energy of combustion of fuels
« on: June 06, 2011, 06:42:47 PM »
I've been given a lab where we create biodiesel from olive oil and methanol. We then use a calorimeter to test the olive oil, the methanol and the biodiesel. Here are the results from my lab. (The image tags aren't working in my post preview so here is a direct link to the results in case: http://i.imgur.com/h2ovK.png ) :

The mass of water used in the calorimeter is 30 g. I am then asked to calculate the energy of combustion per gram of fuel. I came up with an answer but I am unsure if I did it correctly.

I used the formula Q=mc :delta: t. For my mass value I used the mass of the water in the calorimeter (30 g ), for c I used the specific heat capacity of water (4.19 J/(g x C) and for  :delta: t I used the temp change for each fuel. So for Olive oil I have:
=(30 g) x (4.19 J/(g x C)) x (20.1 C)
=2.52657 kJ

Then to get kJ per gram for olive oil I divide that value by the mass of fuel that was burned.

=2.52657 kJ/0.09 g
=28.1 kJ/g

Is this correct?

#### Vidya

• Full Member
• Posts: 839
• Mole Snacks: +46/-62
• Gender:
• Online Chemistry and Organic Chemistry tutor
##### Re: Calculate energy of combustion of fuels
« Reply #1 on: June 11, 2011, 03:25:38 AM »