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April 22, 2021, 09:29:08 am

### AuthorTopic: CHEMISTRY ENTHALPY HSC MCQ  (Read 1328 times) Tweet Share

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#### sangarp

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##### CHEMISTRY ENTHALPY HSC MCQ
« on: November 03, 2019, 01:33:58 pm »
0
Hey need some help on this asap
How do you do this?

#### r1ckworthy

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##### Re: CHEMISTRY ENTHALPY HSC MCQ
« Reply #1 on: November 03, 2019, 01:59:24 pm »
+1
Hey need some help on this asap
How do you do this?

Hey! There might be a quicker way, but from what I can see, I would divide each value on the table to convert it from kJ/ g to kJ/mol. The value that matches 3218 is the correct fuel.
HSC 2019: English Advanced || Mathematics || Mathematics Extension 1 || Physics || Chemistry || Science Extension || Ancient History ||

Bachelor of Physiotherapy @ ACU

The Yr12 journey- a diary I "hope" to update... || Halfway through Year 12... lessons I've learned so far. || Check out my youtube channel!

#### sangarp

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##### Re: CHEMISTRY ENTHALPY HSC MCQ
« Reply #2 on: November 03, 2019, 02:57:03 pm »
0
hey
I actually did that
But I don't seem to get any of the values that have been given

#### r1ckworthy

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##### Re: CHEMISTRY ENTHALPY HSC MCQ
« Reply #3 on: November 03, 2019, 03:28:23 pm »
+3
Sorry! I made a silly mistake- you have to multiply all combustion values with it's molar mass in order to convert it to kJ/mol.

Molar mass comes in the form of g / mol. So, if we multiple the heat of combustion (kJ /g) of each fuel by it's molar mass (g/ mol), we convert the value to kJ /mol. Attached is an example of how I did it for one of the fuels.

Again, sorry for the silly mistake! Another lesson of why you shouldn't do things in your head
HSC 2019: English Advanced || Mathematics || Mathematics Extension 1 || Physics || Chemistry || Science Extension || Ancient History ||

Bachelor of Physiotherapy @ ACU

The Yr12 journey- a diary I "hope" to update... || Halfway through Year 12... lessons I've learned so far. || Check out my youtube channel!