Question

A chemical engineer is studying the following reaction: CH (9)+2H,S(9) CS,(9)+4H (9) At the temperature the engineer picks, the equilibrium constant for this reaction is 2.1. The engineer charges ("fills") four reaction vessels with methane and hydrogen sulfide, and lets the reaction begin. She then measures the composition of the mixture inside each vessel from time to time. Her first set of measurements are shown in the table below. Predict the changes in the compositions the engineer should expect next time she measures the compositions reaction compound pressure expected change in pressure CH 5.94 5.98 at of increase o decrease o increase o decrease of increase I decrease of increase Ol decrease o f increase o 1 decrease o f increase o decrease of increase o decrease of increase Ol decrease of increase o decrease of increase Ol decrease o f increase o decrease o increase o decrease O(no change) O(no change) O(no change) O(no change) O(no change) O(no change) O(no change) O(no change) O(no change) O(no change) O(no change) O(no change) 93135 4.45 atm

Answer 1

Kp = 2.1

A)

Qp = p(CS2)*p(H2)^4 / p(CH4)*p(H2S)^2

= (3.68*1.91^4)/(5.94*5.98^2)

= 0.23

Qp is less to kp

So, reaction will move to the right

CH4: decrease

H2S: decrease

CS2: increase

H2: increase

B)

Qp = p(CS2)*p(H2)^4 / p(CH4)*p(H2S)^2

= (3.62*1.65^4)/(6.00*6.11^2)

= 0.12

Qp is less to kp

So, reaction will move to the right

CH4: decrease

H2S: decrease

CS2: increase

H2: increase

C)

Qp = p(CS2)*p(H2)^4 / p(CH4)*p(H2S)^2

= (4.32*4.45^4)/(5.30*4.71^2)

= 14.4

Qp is greater than kp

So, reaction will move to the left

CH4: increase

H2S: increase

CS2: decrease

H2: decrease