Question

Use the reaction to answer the question.

CO(g) + H2O(g) ⇄ CO2(g) + H2(g) + energy

Which change to the system would be favorable to the forward reaction?

(1 point)
Responses

an increase in the concentration of CO2
an increase in the concentration of CO 2

an increase in the concentration of CO
an increase in the concentration of CO

a decrease in pressure
a decrease in pressure

an increase in pressure

Answer 1

To analyze which change to the system would be favorable to the forward reaction of the equilibrium given by the equation:

\[ \text{CO(g)} + \text{H}_2\text{O(g)} \rightleftharpoons \text{CO}_2\text{(g)} + \text{H}_2\text{(g)} + \text{energy} \]

We apply Le Chatelier's Principle, which states that if an external change is applied to a system at equilibrium, the system will shift in a direction that counteracts that change.

1. **An increase in the concentration of CO2**: This would shift the equilibrium to the left (favoring the reverse reaction) to reduce the concentration of CO2.

2. **An increase in the concentration of CO**: This would shift the equilibrium to the right (favoring the forward reaction) to consume some of the excess CO.

3. **A decrease in pressure**: Since there are 2 moles of gas on the left (1 CO + 1 H2O) and 2 moles of gas on the right (1 CO2 + 1 H2), changing the pressure does not favor either side in terms of gas volume because the number of moles is the same on both sides. Therefore, it would not favor the forward reaction.

4. **An increase in pressure**: This would also not favor the forward reaction for the same reason as above, since there are an equal number of moles of gas on both sides.

The change that would be favorable to the forward reaction is:

**An increase in the concentration of CO**.