Unit 5: Kinetics (copy)

What is the purpose of the rate law in a reaction?

The rate law is based on the initial concentrations of reactants and the rates of product formation and disappearance, requiring experimental data.

What does the Arrhenius constant (k) depend on?

The Arrhenius constant, k, is based on the activation energy for a reaction and the temperature.

For the reaction A + 2B + C → D, which variables are used in the rate law expression?

Rate = k[A]^x[B]^y[C]^z, where x, y, and z represent the order of the reaction with respect to A, B, and C.

How do you determine the exponent in the rate law for reactants?

The exponent is determined by observing how changes in reactant concentrations affect the reaction rate.

What is the rate law derived for reactant A based on experiments 3 and 4?

Rate = k[A]^2[B]^y[C]^z, indicating that the reaction is second order with respect to A.

What is the rate law derived for reactant B based on experiments 1 and 3?

Rate = k[A]^2[B]^1[C]^z, indicating that the reaction is first order with respect to B.

What does an exponent of zero for a reactant indicate?

An exponent of zero indicates that changes in the concentration of that reactant do not affect the reaction rate.

What is the overall order of the reaction for A + 2B + C → D based on the determined orders?

The overall order of the reaction is third order.

How is the rate constant k determined using experimental data?

k can be determined using the formula k = (rate/[A]^2[B]).

What characterizes a zero-order rate law?

In a zero-order reaction, the rate is constant and does not depend on the concentration of reactants.

What is a key feature of first-order rate laws?

In a first-order reaction, the rate is directly proportional to the concentration of one reactant.

How is half-life defined?

Half-life is the time required for half of a substance to react or decay.

What does collision theory state?

Collision theory states that reactions occur when chemicals collide with sufficient energy and the correct orientation.

What role does temperature play in reaction rates?

Increasing temperature generally increases reaction rates because it causes molecules to move faster and collide more effectively.

What are intermediates in reaction mechanisms?

Intermediates are species that are produced in one elementary step and consumed in another.

What is a catalyst?

A catalyst is a substance added to a reaction to speed it up without being consumed in the process.

What is the significance of the rate-determining step in a reaction?

The rate-determining step is the slowest step in a reaction mechanism and determines the overall reaction rate.