NEETChemistryChemical Equilibrium
Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R). Assertion (A): For the synthesis of ammonia ( N ₂ (g) + 3 H ₂ (g) 2 NH ₃ (g) ), the numerical value of K_p is smaller than K_c at 298 K . Reason (R): K_p and K_c are related by the expression K_p = K_c(RT)^ n , where n is the difference between the total number of moles of all products and all reactants. In the l
Options
- ABoth (A) and (R) are correct and (R) is the correct explanation of (A)
- BBoth (A) and (R) are correct but (R) is not the correct explanation of (A)
- C(A) is correct but (R) is not correct
- D(A) is not correct but (R) is correct
Correct answer
C. (A) is correct but (R) is not correct
Step-by-step solution
Assertion (A) is correct: For the reaction N ₂ (g) + 3 H ₂ (g) 2 NH ₃ (g) , the change in gaseous moles is n_g = 2 - (1 + 3) = -2 . The relation is K_p = K_c(RT)⁻² = K_c (RT)^2 . At 298 K , the value of RT is approximately 0.0831 298 24.76 L bar K ⁻¹ mol ⁻¹ , which is significantly greater than 1 . Thus, (RT)^2 > 1 , making K_p Reason (R) is incorrect: The term n (or n_g ) in the relation K_p = K_c(RT)^ n_g specifically represents the difference between the number of moles of gaseous products and gaseous reactants,