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hess's cycle

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    • Thread Starter

    Can someone explain how we calculate the enthalpy change of a reaction and how i would draw a hess's cycle for it ?

    It depends on what values you have been given, i.e. enthalpy change of formation or combustion.
    Name:  Photo on 08-06-2016 at 09.51.jpg
Views: 29
Size:  97.1 KBIf you add all of the values for a specific reaction pathway/arrow, remembering to multiply enthalpy by the number of moles in the equation for each molecule (e.g. if there was 2H2O in the equation and the enthalpy change of formation was -286kJmol-1, then you would do -286x2 = -572kJ).

    Name:  Photo on 08-06-2016 at 10.03.jpg
Views: 24
Size:  62.2 KBThen this, sorry I left this bit out
    • Thread Starter

    ah okay thankyou!
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