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VCE Stuff => VCE Science => VCE Mathematics/Science/Technology => VCE Subjects + Help => VCE Chemistry => Topic started by: you0006 on September 22, 2011, 07:54:58 pm

Title: How do you convert from kj/mol --> kj/g
Post by: you0006 on September 22, 2011, 07:54:58 pm

looking more specifically at VCAA 2010 Q 1 b ii

CH₄ + H₂O  <---> CO 3H₂      Change in H = +207 kj/mol


If 3 mols of Hydrogen can absorb 207 KJ then how can i work out how much 1 gram releases?

Title: Re: How do you convert from kj/mol --> kj/g
Post by: Vincezor on September 22, 2011, 09:04:06 pm

Well, I think you got tricked into thinking that you needed that equation to answer the question.

What you really need is to look in the data book for the heat of combustion for which it will state it is -286kJ/mol

as , the energy density will be 143kJ/g

Tricky eh? :P