Question

Select the best single answer. The water-gas shift reaction plays a central role in the chemical methods for obtaining cleaner fuels from coal: CO(g) + H2O(g) ⇌ CO2(g) + H2(g) At a given temperature, Kp = 2.7. If 0.13 mol of CO, 0.56 mol of H2O, 0.62 mol of CO2, and 0.61 mol of H2 are put in a 2.0−L flask, in which direction does the reaction proceed?

Answer 1

After calculating the reaction quotient (Q), which is approximately 5.2, and comparing it to the equilibrium constant (Kp), which is 2.7, we can see that Q > Kp. Therefore, the reaction will proceed to the left to reach equilibrium.

Step-by-step explanation:

To determine in which direction the water-gas shift reaction will proceed, we must calculate the reaction quotient Q and compare it to the equilibrium constant Kp. The reaction is given by:

CO(g) + H2O(g) ⇌ CO2(g) + H2(g)

At equilibrium, Kp = 2.7 for this reaction at a given temperature. The reaction quotient Q can be calculated using the partial pressures of the gases, which are proportional to their mole fractions for a given volume. Hence, we can use molar quantities in the same volume as a proxy for partial pressures to calculate Q:

Q = (CO2·H2) / (CO·H2O) = (0.62 mol · 0.61 mol) / (0.13 mol · 0.56 mol) = 0.3782 / 0.0728 ≈ 5.2

Since Q > Kp, the reaction will proceed to the left in order to reach equilibrium.

Answer 2

The reaction will proceed to the left

Step-by-step explanation:

Step 1: The balanced equation

CO(g) + H2O(g) ⇌ CO2(g) + H2(g)

Step 2: Data given

Kp = 2.7

Number of moles of CO = 0.13 mol

Number of moles of H2O = 0.56 mol

Number of moles of CO2 = 0.62 mole

Number of moles of H2 = 0.61 mol

Volume = 2.0L

Step 3: Calculate Q

Pco = 0.13 / 1.92 P

Ph2o = 0.56 / 1.92 P

Pco2 = 0.62/1.92 P

Ph2 =0.61 / 1.92 P

Q = [CO2][H2] / [CO][H2O] = 5.2

Q > Kp The reaction will proceed to the left

The reaction will proceed in the reverse direction in order to increase the concentrations of both CO and H2O and decrease that of CO2 and H2 until Q = K.