Chemistry · The second law of thermodynamics: Spontaneity of processes, Delta S of the universe and Delta G of the system as criteria for spontaneity
Assertion Adsorption is exothermic and spontaneous inspite of the fact that adso
Assertion Adsorption is exothermic and spontaneous inspite of the fact that adsorption is accompained with decrease in entropy. Reason The factor \( T \Delta S \) is lesser than \( \Delta H \)
- A. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion
- B. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion
- C. Assertion is correct but Reason is incorrect
- D. Assertion is incorrect but Reason is correct
Step-by-step solution
Adsorption is exothermic (ΔH negative) and accompanied by a decrease in entropy (ΔS negative). For spontaneity, ΔG = ΔH - TΔS must be negative. Since ΔS is negative, -TΔS is positive, so ΔG = negative (ΔH) + positive (|TΔS|). For ΔG to be negative, |ΔH| must be greater than |TΔS|. The reason states 'TΔS is lesser than ΔH', which is ambiguous: if ΔH is negative and TΔS is negative (since ΔS negative), 'lesser' could be misinterpreted. The correct condition is magnitude comparison: |ΔH| > |TΔS|. Thus the reason is incorrect.
Related MCQs
- Amount of usable energy available for work at uniform temperature and pressure is…
- For the reaction, \longrightarrow \) \) Hence is…
- For a given reaction, \rightleftharpoons \) a t 0^{\circ} C \) and 1 bar, which of the following is true?…
- For the reaction at } \longrightarrow \) } \) and The reaction would be:…
- Fill in the blanks by putting appropriate choices.During adsorption there is -in enthalpy and in the entropy of a system but adsorption is a…