BITSAT2018ChemistryThermodynamics (C)Actual
When the heat of a reaction at constant pressure is - 25 × 10 - 3 cal and entropy change for the reaction is 7 . 4 cal deg - 1 , it is predicted that the reaction at 25 0 C is
Options
- Arevesible
- Bspontaneous
- Cnon-spontaneous
- Dirreversible
Correct answer
B. spontaneous
Step-by-step solution
Heat at constant pressure means enthalpy. i.e., ΔG = ΔH - TΔS ΔH = 2 . 5 × 10 3 cal ΔS = 7 . 4 caldeg - 1 T = 298   K ΔG = ΔH - TΔS = - 25 × 10 3 - 298 × 7 . 4 = - 4705 . 2   cal As the value of ΔG is −4705.2 cal, which is a negative value, so this reaction will be spontaneous. Hence, the process is spontaneous.