The rate law of the overall reaction.
A + B -> C
is rate = k[ A ]^2 Which of the following not increase the rate of a chemical reaction?
a) increasing the temperature of the reaction
b)increasing the concentration of reaction A
c)adding a catalyst for the reaction
d)increasing the concentration of reactant B
e)all of these will increase the rate
also, i was wondering if the answer would be different if the rate order was zero or one? i just want to make sure i understand questions like these.
i asked someone and they told me the answer is D, does anyone know for sure?
(B) is not in the rate expression; therefore, changing (B) will not affect the rate.
If the rate order for A is 1, the answers are the same. If the rate order of A is 0, the rate doesn't depend on A or B.
The rate law of the given reaction is rate = k[ A ]^2, where [ A ] represents the concentration of reactant A. To determine which of the given options will not increase the rate of the reaction, let's analyze each one:
a) Increasing the temperature of the reaction typically increases the rate of a chemical reaction, as it provides more kinetic energy to the molecules, allowing them to collide more frequently and with greater energy. Therefore, option a) is not correct.
b) Increasing the concentration of reactant A, as indicated by the rate law, will directly affect the rate of the reaction. As the concentration of A increases, the rate of the reaction will also increase. Thus, option b) is not correct.
c) Adding a catalyst to the reaction usually increases the rate of the reaction by providing an alternative pathway with lower activation energy. This allows more reactant molecules to overcome the energy barrier and form products more quickly. Hence, option c) is not correct.
d) Increasing the concentration of reactant B will not directly affect the rate of the reaction since the rate law is dependent on the concentration of reactant A, not B. Therefore, option d) is correct.
e) Since options a), b), and c) are incorrect, and only option d) is correct, the answer is d) increasing the concentration of reactant B. This option will not increase the rate of the reaction.
The answer would remain the same if the rate order was zero or one because the rate law equation and the effect of each given option on the reaction rate would still be the same.
To determine which option does not increase the rate of the chemical reaction, we can compare the rate law with the given options.
The given rate law is rate = k[ A ]^2, which means the rate of the reaction depends on the square of the concentration of A.
Let's analyze each option:
a) Increasing the temperature of the reaction: Increasing the temperature usually increases the rate of a chemical reaction.
b) Increasing the concentration of reaction A: Since the rate law depends on the square of [ A ], increasing the concentration of A will significantly increase the rate.
c) Adding a catalyst for the reaction: A catalyst can speed up a reaction by providing an alternative pathway with a lower activation energy, which increases the rate.
d) Increasing the concentration of reactant B: The rate law does not depend on the concentration of B, so increasing the concentration of B will not affect the rate. Therefore, increasing the concentration of B does not increase the rate.
e) All of these will increase the rate: This option suggests that all options mentioned will increase the rate. However, as discussed above, increasing the concentration of reactant B does not increase the rate. Therefore, this option is not correct.
Based on the analysis, the correct answer would be (d) increasing the concentration of reactant B. This conclusion remains the same regardless of whether the rate order is zero or one.
It is important to note that the rate law provided in the question assumes a second-order dependence on [ A ]. If the rate order is different, the answer might change. However, the provided rate law determines the dependencies in this specific case.