Calculating kJ from kJ/mol (1 Viewer)

[omgiloverice]

One component of petrol is octane (C8H18). If the heat of combustion of Octane is -5464 kJ/mol then the heat that would be released by 1g of octane is:
a) 33.67 kJ
b)33670 kJ
c)42.03 kJ
d)162.26 kJ

Through unit analysis I get 47.83 kJ (2d.p) but the answer is 33.67 kJ. Anybody willing to take me through the process?

 

[nerdasdasd]

One component of petrol is octane (C8H18). If the heat of combustion of Octane is -5464 kJ/mol then the heat that would be released by 1g of octane is:
a) 33.67 kJ
b)33670 kJ
c)42.03 kJ
d)162.26 kJ

Through unit analysis I get 47.83 kJ (2d.p) but the answer is 33.67 kJ. Anybody willing to take me through the process?

How much grams is in one mol of octane ? Use that number and divide 5464 by it.
Edit: hmm did you double check the solution ?

 

[omgiloverice]

Yea I did plenty of times but I am not sure if my process was right, but it should be.
What solution did you get?

 

[nerdasdasd]

Yea I did plenty of times but I am not sure if my process was right, but it should be.
What solution did you get?

Same as you. I googled it, and it even said that online.

 

[omgiloverice]

.................................... ill follow this up with my chem teacher.

 

[omgiloverice]

I confirmed it with my teacher, the answer is 47.83kJ/mol

 

[D94]

Check the question again, is it 1 gram or 1 mL?

Had the question been 1 mL then the first option would have been correct.