Final answer:
To determine the direction of the water-gas shift reaction, we compare the reaction quotient (Q) to the equilibrium constant (K) using initial molarities of the involved species in the reaction. Calculating Q involves using the balanced chemical equation and the provided equilibrium concentrations, allowing us to predict if the reaction will proceed towards products or reactants.
Thus option A.is correct answer.
Step-by-step explanation:
Given the conditions specified in the water-gas shift reaction which occurs at equilibrium:
CO(g) + H2O(g) ⇌ CO2(g) + H2(g),
we can infer the direction in which the reaction will proceed by comparing the reaction quotient (Q) to the equilibrium constant (K). If Q is less than K, the reaction will proceed to the right, forming more products (CO2 and H2). If Q is greater than K, the reaction will shift to the left, forming more reactants (CO and H2O).
To calculate Q, the initial concentrations (molarity) of the reactants and products must be determined. Using the balanced chemical equation and given molar amounts of substances within a specified volume, the reaction quotient can be computed. The comparison of Q and K will determine the direction of the reaction.
In scenario (a), the equilibrium constants and the mole amounts given are used to calculate the molarity and then Q. Since K is also provided, it becomes a straightforward matter of comparing Q to K to surmise whether the reaction mixture will shift towards reactants or products. Similar steps are followed for scenario (b) after adjusting the system by adding H2 and removing some H2O.
Thus option A.is correct answer.