JEE Advanced2018ChemistryThermodynamics (C)Actual
For a reaction, A ⇌ P , the plots of A a n d P with time at temperatures T 1 a n d T 2 are given below. If T 2 > T 1 , the correct statement(s) is (are) (Assume ∆ H ⊝ a n d ∆ S ⊝ are independent of temperature and ratio of ln K a t T 1 t o ln K a t T 2 is greater than T 2 / T 1 . Here H, S , G and K are enthalpy, entropy, Gibbs energy and equilibrium constant, respectively.)
Options
- A∆ H ⊝ < 0 , ∆ S ⊝ < 0
- B∆ G ⊝ < 0 , ∆ H ⊝ < 0
- C∆ G ⊝ < 0 , ∆ S ⊝ < 0
- D∆ G ⊝ > 0 , ∆ S ⊝ > 0
Correct answer
A. ∆ H ⊝ < 0 , ∆ S ⊝ < 0
Step-by-step solution
A ⇌ P Given T 2 > T 1 ln ⁡ K 1 ln ⁡ K 2 > T 2 T 1 ⇒     T 1 ln ⁡ k 1 > T 2 ln ⁡ k 2 ⇒   - ∆ G 1 0 > - ∆ G 2 0 ⇒     - ∆ H 0 + T 1 ∆ S 0 > - ∆ H 0 + T 2 ∆ S o ⇒     T 1 ∆ S 0 > T 2 ∆ S 0 ⇒       ∆ S o < 0 At T 2   temperature concentration of product is decreases that shows reaction is exothermic.