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H(2)(g)+(1)/(2)O(2)(g)toH(2)O(l),DeltaH=...

`H_(2)(g)+(1)/(2)O_(2)(g)toH_(2)O(l),DeltaH=-285.8kJ`. What will be the value of `DeltaH` for the reaction: `2H_(2)O(l)to2H_(2)(g) +O_(2)(g)`?

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`H_(2)(g)+(1)/(2)O_(2)(g)toH_(2)O(l),DeltaH=-285.8kJ`
If this reaction is written in the reverse manner, we have
`H_(2)O(l)toH_(2)(g)+(1)/(2)O_(2)(g),DeltaH=+285.8kJ`
Multiplying this equation by 2, we have
`2H_(2)O(l)to2H_(2)(g)+O_(2)(g),DeltaH=+571.6kJ`.
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