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Last min chem questions watch

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    Ok, some last minute chem questions:

    1. Why is the enthalpy of formation of H2 = 0 ???

    2. If you are trying to find the partial pressure of reaction and the reaction is in the form:

    2X ---> Y + Z (where X, Y and Z are gases)

    When using initial moles in the reaction mixture, do you use the initial moles of X as 2 or as 1 (Was reminded by a similar question that was on the Edexcel chemistry Unit 4 paper)

    Thanks everyone!!!

    Also good luck to everyone in their final exams!!!!
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    (Original post by Silly Sally)
    Ok, some last minute chem questions:

    1. Why is the enthalpy of formation of H2 = 0 ???

    2. If you are trying to find the partial pressure of reaction and the reaction is in the form:

    2X ---> Y + Z (where X, Y and Z are gases)

    When using initial moles in the reaction mixture, do you use the initial moles of X as 2 or as 1 (Was reminded by a similar question that was on the Edexcel chemistry Unit 4 paper)

    Thanks everyone!!!

    Also good luck to everyone in their final exams!!!!

    1. Because you need to form it from its consituent elements in their standard state - H2 is a diatomic molecule, so you're just forming H2 from H2, which requires no energy!

    2. 2.
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    (Original post by Turbonutter)
    1. Because you need to form it from its consituent elements in their standard state - H2 is a diatomic molecule, so you're just forming H2 from H2, which requires no energy!

    2. 2.
    Thanks!!!
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    [QUOTE=Silly Sally]Ok, some last minute chem questions:

    1. Why is the enthalpy of formation of H2 = 0 ???

    2. If you are trying to find the partial pressure of reaction and the reaction is in the form:

    2X ---> Y + Z (where X, Y and Z are gases)

    When using initial moles in the reaction mixture, do you use the initial moles of X as 2 or as 1 (Was reminded by a similar question that was on the Edexcel chemistry Unit 4 paper)



    2. its common sense....
 
 
 
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