InterviewSolution
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InterviewSolution
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The value of `DeltaH` and `DeltaS` for the reaction `C_("(graphite)") +CO_92)(g) rarr 2CO(g0` are170 kJ and `170JK^(-1)` respectively. This reaction will be spontaneous atA. 910 KB. 1110KC. 510KD. 710 K |
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Answer» Correct Answer - B `DeltaG =DeltaH - T DeltaS`. For reaction to be spontaneous `DeltaS` should be -ve, i.e.,`DeltaH-TDetlaS lt0 `or `DeltaHlt T DeltaS` or `TDeltaS gt DeltaH ` or`Tgt ( DeltaH )/( DeltaS) , i.e.,T gt (170000J)/( 170 JK^(-1))` or `T gt 1000K`. Hence, options (b) iscorrect. This method can be applied only when `DeltaH` and`DeltaS` both are `+ve`. Alternatively, for equilibrium , `DeltaG =0` `i.e., T DeltaS = DeltaH` or `T= ( DeltaH )/( DeltaS) =( 170000)/( 170) =1000K` For spontaneity , `DeltaG = -ve`which can be so if `T gt 1000 K` ( so that`T DeltaS gt DetalH` in magnitude ) . |
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