The standard entropies of `N_(2)(g),H_(2)(g)` and `NH_(3)(g)` are `191.5, 130.5,192.6JK^(-1)mol^(-1)` . The value of `DeltaS^(0)` during the formation

Monjur Alahi

The standard entropies of `N_(2)(g),H_(2)(g)` and `NH_(3)(g)` are `191.5, 130.5,192.6JK^(-1)mol^(-1)` . The value of `DeltaS^(0)` during the formation of 1 mole of ammonia is
A. `-98.9JK^(-1)mol^(-1)`
B. zero
C. `+129.4JK^(-1)mol^(-1)`
D. `-29.4JK^(-1)mol^(-1)`


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Salim Ahmed Kawsar

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Correct Answer - A
Formation of `NH_(3)` is
`(1)/(2) N_(2)+(3)/(2)H_(2)toNH_(3)`
`DeltaS^(@)=192.6-(1)/(2)(191.5)-(3)/(2)(130.5)`
`=-98.9 JK^(-1) mol^(-1)`

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