[matt1234]

Hello,
I have the following question in my text:
Alternative transportation fuels include methanol and hydrogen.
(a) Use standard enthalpies of formation to calculate the energy produced per
mole of methanol burned.

Answer 22.7 MJ/mol

(b) Use standard enthalpies of formation to calculate the energy produced per
mole of hydrogen burned.

Answer  142 MJ/mol

Now i havent started part b yet since i have no idea how they got such a large figure for part a.  I got -726 Kj/mol according to the reaction.

Below is my attempt:

Please advise.

[cliverlong]

1. Your equation for the combustion of methanol isn't balanced

2. Are you absolutely sure the provided answer has units MJ mol^-1 ??

Clive

[matt1234]

Sorry your correct should have been 3/2 for Oxygen now i should be multiplying the equation by two.  Im sure the units are MJ/mol.  here is the ebook version of my text:  

http://www2.kpr.edu.on.ca/cdciw/science/12U_chemistry/12U%20chemistry%20textbook/Attachments/a)_Student_Text/C12SB331.pdf


Pg 9 in the PDF # 9a

[cliverlong]

The following

http://www.avogadro.co.uk/calculations/method3.htm

gives same result as you using same data and same  :delta: H_f method.

Clive