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    The heat of combustion of C2H6 is highly exothermic but C2H6 does not spontaneously burst into flames. Explain why?

    Any ideas?
    Thanks x
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    (Original post by gemstar!)
    The heat of combustion of C2H6 is highly exothermic but C2H6 does not spontaneously burst into flames. Explain why?

    Any ideas?
    Thanks x
    What do you know about the activation energy?
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    (Original post by Potassium^2)
    What do you know about the activation energy?
    Nothing! That's the only piece of information i've been given
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    (Original post by gemstar!)
    Nothing! That's the only piece of information i've been given
    Okay, do you know what activation energy is in general?

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    The minimum amount of energy needed to start a reaction


    How does this apply here?
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    (Original post by Potassium^2)
    Okay, do you know what activation energy is in general?

    Spoiler:
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    The minimum amount of energy needed to start a reaction


    How does this apply here?
    So ethene's activation energy is too high?
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    (Original post by gemstar!)
    So ethene's activation energy is too high?
    Yeah It's too high so unless energy is provided (i.e heat), it won't have enough energy to overcome the initial activation energy.
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    (Original post by gemstar!)
    The heat of combustion of C2H6 is highly exothermic but C2H6 does not spontaneously burst into flames. Explain why?

    Any ideas?
    Thanks x
    The enthalpy of a reaction doesn't tell you anything about whether that reaction will actually happen. Combustion enthalpies are always negative, but things don't just go around spontaneously combusting (apart from some old ladies).

    Look at the diagram.
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