Question

Methane, CH4, reacts with I2 according to the reaction CH4(g)+I2(g)⇌CH3I(g)+HI(g) At 630 K, Kp for this reaction is 2.26×10−4. A reaction was set up at 630 K with initial partial pressures of methane of 105.1 torr and of 7.96 torr for I2.

Part A Calculate the pressure, in torr, of CH4. Express your answer to four significant figures and include the appropriate units. SubmitMy AnswersGive Up Part B Calculate the pressure, in torr, of I2. Express your answer to three significant figures and include the appropriate units. SubmitMy AnswersGive Up Part C Calculate the pressure, in torr, of CH3I. Express your answer to three significant figures and include the appropriate units. SubmitMy AnswersGive Up Part D Calculate the pressure, in torr, of HI.

Answer 1

CH4(g)+I2(g)⇌CH3I(g)+HI(g)

At 630 K, Kp = 2.26×10−4 and initial partial pressures of methane = 105.1 torr and of 7.96 torr for I2.

CH4(g) +    I2(g)⇌                 CH3I(g)+          HI(g)

I           105.1 torr        7.96 torr             0                  0
C                     -x         -x                        +x                 +x
E........ (105.1-x)          (7.96-x)                x                 x

Kp= x^2/ (105.1-x)(7.96-x)

X= 0.42217 torr

At equilibrium pressure of CH4 = 105.1-x= 105.1-0.42217 torr = 104.7 torr

At equilibrium pressure of I2 = 7.96-x = 7.96-0.42217 torr = 7.54 torr

At equilibrium pressure of CH3I =0.42217 torr

At equilibrium pressure of HI =0.42217 torr