Ch.15 - Chemical Kinetics

Problem 37c

Chapter 15, Problem 37c

This graph shows a plot of the rate of a reaction versus the concentration of the reactant A for the reaction A → products. c. Write a rate law for the reaction including an estimate for the value of k.

Verified step by step guidance

Identify the order of the reaction by analyzing the graph. If the rate is directly proportional to the concentration of A, it is first order. If the rate is proportional to the square of the concentration of A, it is second order.

Write the general form of the rate law based on the order determined. For a first-order reaction, the rate law is: rate = k[A]. For a second-order reaction, the rate law is: rate = k[A]^2.

Estimate the value of the rate constant k by using a point from the graph. Choose a point where the concentration of A and the corresponding rate are given.

Substitute the values of the concentration of A and the rate into the rate law equation to solve for k.

Express the rate law with the estimated value of k, including the units of k based on the order of the reaction.

Verified video answer for a similar problem:

This video solution was recommended by our tutors as helpful for the problem above.

Video duration:

Was this helpful?

Key Concepts

Here are the essential concepts you must grasp in order to answer the question correctly.

Rate Law

The rate law expresses the relationship between the rate of a chemical reaction and the concentration of its reactants. It is typically formulated as rate = k[A]^n, where k is the rate constant, [A] is the concentration of reactant A, and n is the order of the reaction with respect to A. The order can be determined experimentally and indicates how the rate is affected by changes in concentration.

Reaction Order

The reaction order is a key concept in kinetics that describes how the rate of a reaction depends on the concentration of reactants. It can be zero, first, second, or higher, depending on how the rate changes with varying concentrations. For example, a first-order reaction means that doubling the concentration of the reactant will double the reaction rate.

Rate Constant (k)

The rate constant, denoted as k, is a proportionality factor in the rate law that is specific to a given reaction at a particular temperature. It reflects the speed of the reaction; a larger k indicates a faster reaction. The value of k can be determined experimentally and is influenced by factors such as temperature and the presence of catalysts.

Recommended video:

Guided course

01:14

Equilibrium Constant K

Related Practice

Open Question

Consider the reaction: 2 H2O2(aq) → 2 H2O(l) + O2(g). The graph shows the concentration of H2O2 as a function of time. Use the graph to calculate each quantity: a. the average rate of the reaction between 10 and 20 seconds, b. the instantaneous rate of the reaction at 30 seconds.

Textbook Question

Consider the reaction: 2 H₂O₂(aq) → 2 H₂O(l ) + O₂( g) The graph shows the concentration of H₂O₂ as a function of time. Use the graph to calculate each quantity: d. If the initial volume of the H₂O₂ is 1.5 L, what total amount of O₂ (in moles) is formed in the first 50 s of reaction?

1317

views

Textbook Question

This graph shows a plot of the rate of a reaction versus the concentration of the reactant A for the reaction A → products. a. What is the order of the reaction with respect to A?

534

views

Textbook Question

This graph shows a plot of the rate of a reaction versus the concentration of the reactant.

a. What is the order of the reaction with respect to A?

480

views

Textbook Question

This graph shows a plot of the rate of a reaction versus the concentration of the reactant.

b. Make a rough sketch of a plot of [A] versus time

844

views

Textbook Question

This graph shows a plot of the rate of a reaction versus the concentration of the reactant.

c. Write a rate law for the reaction including the value of k.

492

views