Catalysis and Reaction Rates

In the catalytic formation of $SO_3$ using nitric oxide (NO), what role does $NO_2$ play according to the proposed mechanism?

Which characteristic is most crucial for a solid catalyst used in the hydrogenation of vegetable oil?

What is the primary function of the mixture of Pd, Pt, and Rh in an automobile catalytic converter?

Given the reactions:

$CO(g) + 3H_2(g) \xrightarrow{Ni-catalyst} CH_4(g) + H_2O(g)$

$CO(g) + 2H_2(g) \xrightarrow{ZnO-Cr_2O_3 Catalyst} CH_3OH(g)$

What can be concluded about catalysts?

In enzyme-catalyzed reactions, how do enzymes affect the activation energy?

Which type of rate is most useful for determining the rate law of a reaction because it minimizes the impact of product concentrations?

A reaction's rate is measured at different times, and the data is plotted. How would you determine the instantaneous rate at a specific time point on the graph?

Consider a reaction where the concentration of a reactant decreases from 0.1 M to 0.05 M in 20 seconds. Which statement accurately describes how the average rate of this reaction should be expressed?

In a study of chemical kinetics, why is it important to understand the stoichiometric relationships between reactants and products?

What is the primary purpose of determining the rate law for a chemical reaction?

How does understanding the reaction mechanism aid in chemical kinetics?

A chemist performs a reaction with and without a catalyst and measures the reaction rate in both scenarios. What key difference would be observed when a catalyst is used?

Why is the determination of activation energy important in chemical kinetics?

Why is determining the rate law of a reaction significant?

In the rate law expression, Rate = k[A]^x[B]^y, what do 'x' and 'y' represent?

For the reaction 2N2O5 -> 4NO2 + O2, if the rate of formation of NO2 is 0.08 M/s, what is the rate of disappearance of N2O5?

Consider the rate law: Rate = k[A]^2[B]. What is the overall order of the reaction?

In a zero-order reaction, how does changing the concentration of the reactant affect the reaction rate?

Given the reaction aA + bB -> cC + dD, which expression accurately represents the relationship between the rates of disappearance of reactants and appearance of products?

For a first-order reaction, if the rate constant k is 0.05 s^-1, what does this indicate about the reaction?

Consider a reaction with the rate law Rate = k[A][B]^0. If the concentration of A is doubled, what happens to the reaction rate?

In an experiment, the initial rate of a reaction between $S_2O_8^{2-}$ and $I^-$ is measured at two different concentrations of $S_2O_8^{2-}$, while keeping the $I^-$ concentration constant. If doubling the concentration of $S_2O_8^{2-}$ doubles the initial rate, what is the order of the reaction with respect to $S_2O_8^{2-}$?

Consider a reaction where the rate law is given by $Rate = k[S_2O_8^{2-}] [I^-]$. If the initial concentrations are $[S_2O_8^{2-}] = 0.1 M$ and $[I^-] = 0.2 M$, and the rate constant $k = 5 \times 10^{-3} L \cdot mol^{-1} \cdot s^{-1}$, what is the initial rate of the reaction?

For a zero-order reaction, a plot of reactant concentration $[R]_t$ versus time $t$ yields a straight line. What does the slope of this line represent?

The reaction between $S_2O_8^{2-}$ and $I^-$ is found to be first order with respect to both reactants. If the concentration of $S_2O_8^{2-}$ is doubled and the concentration of $I^-$ is halved, how will the rate of the reaction change?

In a reaction with rate law $Rate = k[S_2O_8^{2-}] [I^-]$, the rate constant $k$ is determined to be $4.6 \times 10^{-3} L \cdot mol^{-1} \cdot s^{-1}$ at a certain temperature. If the concentrations of both $S_2O_8^{2-}$ and $I^-$ are $0.30 M$, what is the rate of the reaction?

For the reaction $2NO_2(g) \rightarrow 2NO(g) + O_2(g)$, what is the correct interpretation of the rate law expression, Rate = $k[NO_2]^n$?

Consider a reaction where the rate law is given by Rate = $k[A]^2[B]$. What will happen to the reaction rate if the concentration of A is doubled and the concentration of B is halved?

Which statement best describes the relationship between differential and integrated rate laws?

In determining the rate law for a reaction, why are the concentrations of products usually excluded?

For a reaction $R1 + R2 \rightarrow Products$, the experimentally determined rate law is Rate = $k[R1]^x[R2]^y$. What do the exponents x and y signify?

If the average rate of a reaction decreases as the reaction progresses, which of the following is the most likely reason?

The initial concentration of a reactant is 0.200 mol/L. After 60 seconds, the concentration drops to 0.100 mol/L. Assuming first-order kinetics, what is the approximate half-life of this reaction?

For the reaction $2NO_2(g) \rightarrow 2NO(g) + O_2(g)$, if the rate of formation of $O_2$ is $2.0 \times 10^{-6}$ mol/(L⋅s), what is the rate of decomposition of $NO_2$?

For a reaction A → products, if the initial concentration of A is 8.0 M and after 60 seconds the concentration is 6.0 M, and the reaction is zero order, what is the rate constant (k)?

A reaction mechanism consists of several elementary steps. Which statement regarding the relationship between the elementary steps and the overall balanced equation is correct?

Consider a reaction with the experimental rate law: Rate = k[A]^2[B]. Which of the following elementary steps is consistent with this rate law?

For the reaction $2N_2O_5(g) \rightarrow 4NO_2(g) + O_2(g)$, the proposed mechanism is:

Step 1: $N_2O_5 \rightleftharpoons NO_2 + NO_3$ (fast) Step 2: $NO_2 + NO_3 \rightarrow NO + O_2 + NO_2$ (slow) Step 3: $NO_3 + NO \rightarrow 2NO_2$ (fast)

What is the molecularity of the rate-determining step?

What is the half-life of a first-order reaction if the rate constant is $7.0 \times 10^{-4} s^{-1}$?

Consider the following reaction mechanism:

Step 1: $A + B \rightarrow C$ (slow) Step 2: $C + A \rightarrow D$ (fast)

Which of the following rate laws is consistent with this mechanism?

For a reaction to occur effectively, reactant molecules must collide with the proper orientation and sufficient energy. What is the term for the minimum energy required for a collision to result in a reaction?

A proposed mechanism for a reaction is:

Step 1: $Cl_2(g) \rightleftharpoons 2Cl(g)$ (fast equilibrium) Step 2: $Cl(g) + CHCl_3(g) \rightarrow HCl(g) + CCl_3(g)$ (slow) Step 3: $CCl_3(g) + Cl(g) \rightarrow CCl_4(g)$ (fast)

What is the overall order of the reaction predicted by this mechanism?