All of the following apply to the reaction A(g)+B(g)<==>C(g) as it is carried out at constant temperature in a rigid container EXCEPT:
A)The total pressure decreases
B)The rate of reaction decreases
C)The entropy of the system decreases
D)The number of molecules of C decreases
E)The frequency of collisions between molecule A and B decreases
Look at D as a possible answer.
To determine which option does NOT apply to the given reaction, we need to understand some basic principles.
In a reversible reaction like the one given (A(g) + B(g) ⇌ C(g)), the reaction can happen in both the forward and reverse directions simultaneously. At equilibrium, the rates of the forward and reverse reactions are equal, and there is no net change in the concentrations of the reactants and products.
Now, let's analyze each option:
A) The total pressure decreases: In a reaction where the number of moles of gas molecules decreases from the reactants to the products, like in this case (A + B ⇌ C), it generally results in a decrease in total pressure. This option seems plausible.
B) The rate of reaction decreases: Since the reaction is carried out at a constant temperature, the rate of reaction should not change. However, keep in mind that the rate of the forward reaction is equal to the rate of the reverse reaction at equilibrium. This option also seems plausible.
C) The entropy of the system decreases: Entropy is a measure of the system's disorder, and it generally tends to increase in chemical reactions. In this case, if the number of gas molecules decreases from reactants to products, it suggests a decrease in entropy. This option seems plausible.
D) The number of molecules of C decreases: The given reaction involves the formation of C from A and B. Therefore, the number of molecules of C should increase or remain the same at equilibrium, not decrease. This is a potential answer.
E) The frequency of collisions between molecule A and B decreases: The reaction rate is directly proportional to the frequency of collisions between reactant molecules. However, since the temperature is constant, it does not affect the frequency of collisions. This option seems plausible.
Based on the analysis, the answer that does NOT apply to the given reaction is:
D) The number of molecules of C decreases
To get this answer, we need to identify that at equilibrium, the number of molecules of C either increases or remains the same, implying that it does not decrease.