NEET Solved Paper 2017 Question 31
Question: For a given reaction, $ \Delta =35.5,kJ,mo{l^{-1}} $ and $ \Delta S=83.6,J{K^{-1}},mo{l^{-1}}. $ The reaction is spontaneous at : (Assume that $ \Delta H $ and $ \Delta S $ do not vary with temperature)
Options:
A) T > 298 K
B) T < 425 K
C) T > 425 K
D) All temperatures
Show Answer
Answer:
Correct Answer: C
Solution:
- $ \because $ $ \Delta G=\Delta H-T\Delta S $ For a reaction to be spontaneous, $ \Delta G=-ve $ i.e., $ \Delta H<T\Delta S $
$ \therefore $ $ T>\frac{\Delta }{\Delta S}=\frac{35.5\times 10^{3}J}{83.6,J{K^{-1}}} $ i.e., T > 425 K
