Question

For the following reaction, Kc = 255 at 1000 K. CO (g) + Cl2 (g) ? COCl2 (g) Part A. If a reaction mixture initially contains a CO concentration of 0.1510 and a Cl2 concentration of 0.180 at 1000K. What is the equilibrium concentration of CO at 1000 K? Part B. What is the equilibrium concentration of Cl2 at 1000 K? Part C What is the equilibrium concentration of COCl2 at 1000 K? Express all answers in molarity to three significant figures

Answer 1

CO + Cl2 = COCl2

                        CO              Cl2                COCl2

initial       0.1510           0.180        0

change       -x                     -x                        + x

At equillibrium    0.1510 -x         0.180 -x                 x

K= 255 = [COCl2 ] / [CO] [Cl2]

255 = x / (0.1510 -x) ( 0.180 -x)

255 = x / 0.02718 - 0.1510x -0.180 x + x²

255 = x / 0.02718 -0.331 x + x²

255 (0.02718 -0.331 x + x² ) = x

6.9309 - 84.405 x + 255 x ² = x

x = 0.08123

[CO] = 0.1510 - 0.081 = 0.06977 =0.0698

[Cl2] = 0.180 - 0.081 = 0.09877 =0.0988

[COCl2] = 0.08123 = 0.0812