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Author Topic: chemistry:enthalpy changes !!!!!!  (Read 661 times)

Offline ruby92

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chemistry:enthalpy changes !!!!!!
« on: March 17, 2010, 02:47:36 pm »
the chief gas in bio gas is methane
(a)the standard enthalphy change of formation deltaHf (CH4) cannot be measured directly.
i calculate the standard enthalpy change of formation of methane from the deltaHc values below
     substance        deltaHc
CH4                          -890
C                             -393.5
H2                            -285.9

ii suggest why the enthalpy change of formation of methane cannot be measured directly?
« Last Edit: March 17, 2010, 03:47:39 pm by ruby92 »
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Offline Saladin

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Re: chemistry:enthalpy changes !!!!!!
« Reply #1 on: March 18, 2010, 04:47:37 am »
There u go.
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Offline ruby92

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Re: chemistry:enthalpy changes !!!!!!
« Reply #2 on: March 18, 2010, 03:32:07 pm »
thnk u so muchhh :D
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