Question

Use the References to access important values if needed for this question. Consider the following system at equilibrium where AH° = -87.9 kJ, and Kc = 83.3 , at 500 K: PC13 (g) + Cl2 (g) = PC1s (g) If the TEMPERATURE on the equilibrium system is suddenly increased : The value of KL A . Increases B. Decreases C. Remains the same The value of QcL A . Is greater than Kc B. Is equal to K C. Is less than Kc The reaction must: A. Run in the forward direction to restablish equilibrium. B. Run in the reverse direction to restablish equilibrium. C. Remain the same. Already at equilibrium. The concentration of Cl, will: A. Increase B. Decrease. C. Remain the same.

Answer 1

Increasing Temperature will shift the reaction in a direction which absorbs heat as per Le chatelier Principle

Forward reaction is exothermic in nature

hence, backward reaction will be favoured

So, Equilibrium moves to reactant side and hence Kc decreases

1)

The value of Kc Decreases

Answer: B

2)

Since Kc decreases, Qc > Kc

Answer: A

3)

Since Qc > Kc, the reaction must run in reverse direction

Answer: B

4)

Since reaction runs in reverse direction and Cl2 is reactant.

So, concentration of Cl2 increases.

Answer: A