Consider the reaction PCl₅(g) →PCl₃(g)+ Cl₂(g) At a certain temperature,if the initial concentration of PCl₅(g)is 2.0 M,at equilibrium the concentration of Cl₂(g)is 0.30 M.Calculate the value of K_c at this temperature.

Question

Quizplus · Accepted Answer

The balanced equation for the reaction is:
PCl5(g) → PCl3(g) + Cl2(g)
Let’s assume the equilibrium concentration of PCl5 is x M.
The concentration of PCl3 will then be (2.0 – x) M, and the concentration of Cl2 will also be (2.0 – x) M.
The equilibrium constant, Kc, for the reaction is given by:
Kc = [PCl3][Cl2] / [PCl5]
Kc = [(2.0 – x)(2.0 – x)] / x = (4.0 – 4x + x^2) / x
At equilibrium, the concentration of Cl2 is 0.30 M. Therefore, we have:
0.30 = 2.0 – x
x = 1.70 M
Substituting x = 1.70 M into the expression for Kc, we obtain:
Kc = (4.0 – 4x + x^2) / x = (4.0 – 6.8 + 2.89) / 1.70 = 0.053 M^-1
Therefore, the answer is B.

Consider the Reaction PCl5(g) →PCl3(g)+ Cl2(g)

Consider the Reaction PCl₅(g) →PCl₃(g)+ Cl₂(g)