NTA Abhyas NEET2020ChemistryChemical EquilibriumPractice
For the gas phase reaction, P C l 5 ( g ) ⇌ P C l 3 ( g ) + C l 2 ( g ) Which of the following conditions are correct?
Options
- AΔ H < 0 and Δ S < 0
- BΔ H > 0 and Δ S < 0
- CΔ H = 0 and Δ S < 0
- DΔ H > 0 and Δ S > 0
Correct answer
D. Δ H > 0 and Δ S > 0
Step-by-step solution
Gas phase reaction P C l 5 ( g ) ⇌ P C l 3 ( g ) + C l 2 ( g ) Δ H = Δ E + Δ n g R T Δ n = change in number of moles of product and reactant species. Since Δ n g = + v e , hence Δ H = + v e also one mole of P C l 5 is dissociated into two moles of P C l 3 and C l 2 in the same phase. Therefore, Δ S = S p r o d u c t - S r e a c t a n t Δ S = + v e