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The standard enthalpy of formation of ga...

The standard enthalpy of formation of gaseous `H_(2)O` at 298 K is `-241.82` kJ/mol. Calculate `DeltaH^(@)` at 373 K given the following values of the molar heat capacities at constant pressure :
`H_(2)O(g)=33.58 " JK"^(-1)" mol"^(-1), " "H_(2)(g)=29.84 " JK"^(-1)" mol"^(-1), " "O_(2)(g)=29.37 " JK"^(-1)" mol"^(-1)`
Assume that the heat capacities are independent of temperature :

A

`-"242.6 kJ mol"^(-1)`

B

`-"485.2 kJ mol"^(-1)`

C

`-"121.3 kJ mol"^(-1)`

D

`-"286.4 kJ mol"^(-1)`

Text Solution

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The correct Answer is:
A
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