[lilns8252]

I have a couple homework questions due tonight and i've tried everything but i dont seem to understand!!!
the question is:

Using enthalpies of formation, calculate the quantity of heat produced when 4.65  of butane is completely combusted in air under standard conditions. The answer should be in kJ

[typhoon2028]

4.65 what?  Units?  (grams, kilograms, pounds, moles)

After you know that, calculate the heat of formation of butane.  This should be in kJ/mole.

[ARGOS++]

Dear nimritsohal;

This page should be of help to you:
      http://en.wikipedia.org/wiki/Standard_enthalpy_change_of_formation
And please use units!: What is 4.65 meaning grams, or kg, or moles?

Good Luck!
                    ARGOS⁺⁺

[lilns8252]

sorry i forgotto add the units.. it was 4.65 grams

[lilns8252]

I solved for heat of formation of butane and got -5271kJ/mol... what do i do after that?? or is that the answer? because the units they want the answer in is just kJ.. wat happends to the moles then?

[ARGOS++]

Dear nimritsohal;

If I’m correct, then Wiki reports another value than you:
            http://en.wikipedia.org/wiki/Butane_(data_page)

What's also required is a balanced reaction equation!

Good Luck!
                    ARGOS⁺⁺