Q: For the reaction $$aA + bB \rightarrow cC + dD$$, which of the following correctly expresses the rate of reaction?

$$\text{Rate} = -\frac{\Delta [A]}{a \Delta t} = -\frac{\Delta [B]}{b \Delta t} = +\frac{\Delta [C]}{c \Delta t} = +\frac{\Delta [D]}{d \Delta t}$$

Q: In the reaction $$2N_2O_5(g) \rightarrow 4NO_2(g) + O_2$(g)$$, if the rate of disappearance of $$N_2O_5 is$$ $$2.0 \times 10$$^{-3}$$ mol L$$^{-1}$$ s$$^{-1}$$, what is the rate of appearance of NO_2$?

$$4.0 \times 10$$^{-3}$$ mol L$$^{-1}$$ s$$^{-1}$$

Question 1

Which of the following best describes the primary focus of chemical kinetics?

Accepted Answer

The study of the rates at which chemical reactions occur.

Question 2

For the reaction $$aA + bB \rightarrow cC + dD$$, which of the following correctly expresses the rate of reaction?

Accepted Answer

$$	ext{Rate} = -\frac{\Delta [A]}{a \Delta t} = -\frac{\Delta [B]}{b \Delta t} = +\frac{\Delta [C]}{c \Delta t} = +\frac{\Delta [D]}{d \Delta t}$$

Question 3

In the reaction $$2N_2O_5(g) ightarrow 4NO_2(g) + O_2$(g)$$, if the rate of disappearance of $$N_2O_5 is$$ $$2.0 	imes 10$$^{-3}$$ mol L$$^{-1}$$ s$$^{-1}$$, what is the rate of appearance of NO_2$?

Accepted Answer

$$4.0 	imes 10$$^{-3}$$ mol L$$^{-1}$$ s$$^{-1}$$

Question 4

Which factor does NOT directly affect the rate of a chemical reaction?

Accepted Answer

Color of the reactants

Question 5

Given the rate law $$	ext{Rate} = k[A]^2[B]$$, what is the overall order of the reaction?

Accepted Answer

Third order

Question 6

Which statement about the rate constant $$k is $$TRUE?

Accepted Answer

It is affected by the presence of a catalyst.

Question 7

A reaction has the rate law $$	ext{Rate} = k[A][B]^2. If $$the concentration of $$A is $$doubled and $$B is $$tripled, by what factor does the rate increase?

Accepted Answer

18

Question 8

Which of the following is a correct statement about collision theory?

Accepted Answer

Only collisions with sufficient kinetic energy and proper orientation lead to a reaction.

Question 9

According to the Arrhenius equation $$k = Ae$$^{-E_a/RT}$$, what happens to the rate constant k$ as temperature increases?

Accepted Answer

It increases.

Question 10

Which of the following best describes the transition state in a chemical reaction?

Accepted Answer

A short-lived, high-energy species formed during the reaction.

Question 11

For the reaction $$A + B ightarrow \,	ext{Products}$$, initial rate data shows that doubling $$[A]$$ doubles the rate, but doubling $$[B]$$ quadruples the rate. What is the correct rate law?

Accepted Answer

$$	ext{Rate} = k[A][B]^2$$

Question 12

Which of the following is NOT a reason to study chemical kinetics?

Accepted Answer

To determine the molecular structure of reactants.

Question 13

In a reaction mechanism, what is the rate-determining step?

Accepted Answer

The slowest elementary step.

Question 14

Which of the following is an example of a bimolecular elementary reaction?

Accepted Answer

$$NO(g) + O_3$(g) \rightarrow NO_2$(g) + O_2$(g)$$

Question 15

If the activation energy $$E_a$$ for a reaction is high, what can be inferred about the reaction rate at room temperature?

Accepted Answer

The reaction rate will be very slow.

Question 16

Which of the following statements about catalysts is TRUE?

Accepted Answer

Catalysts provide an alternative pathway with lower activation energy.

Question 17

A student measures the concentration of reactant $$A$$ over time and finds that the rate of disappearance of $$A$$ decreases as the reaction proceeds. What is the most likely explanation?

Accepted Answer

The concentration of $$A is $$decreasing.

Question 18

Which of the following is the correct Arrhenius equation?

Accepted Answer

$$k = Ae$$^{-E_a/RT}$$

Question 19

In the Maxwell-Boltzmann distribution, what does increasing the temperature do to the distribution of molecular kinetic energies?

Accepted Answer

It shifts the distribution to higher energies.

Question 20

Which of the following is a correct statement about reaction intermediates?

Accepted Answer

They are formed and consumed during the reaction mechanism.

Chemical Kinetics: Study Notes

Guida di studio - Domande di pratica

Study guide - Flashcard