Chapter 14: Problem 36

Once a reaction begins, the rate of the reverse reaction gradually speeds up. Explain why this is so.

Short Answer

Expert verified

In a reversible chemical reaction, the system eventually reaches a state of equilibrium, where the rate of the forward and reverse reactions is equal. Initially, there are more reactants than products, so the forward reaction is more prevalent. As reactants are converted into products, the concentration of products increases, leading to an increased likelihood of the reverse reaction occurring. As a result, the rate of the reverse reaction gradually speeds up until it becomes equal to the rate of the forward reaction, re-establishing equilibrium.

Step by step solution

Introduction to Chemical Equilibria and Reaction Rates

In a reversible chemical reaction, reactants are converted into products, and products are converted back into reactants. As these forward and reverse reactions occur simultaneously, the concentration of reactants and products change over time. Eventually, the system reaches a state of equilibrium, where the rate of the forward and reverse reactions is equal, and the concentration of the reactants and products no longer change.

Le Chatelier's Principle

Le Chatelier's Principle states that if a system in equilibrium is subjected to a change in concentration of the reactants or products, the system will adjust the equilibrium to counteract the effect of the change. This happens in such a way as to minimize the change, and restore the equilibrium condition.

Initial Reaction Rates

At the beginning of a reaction, there are usually more reactants than products. Consequently, the forward reaction is initially more prevalent than the reverse reaction, as there is a higher concentration of reactants. As the forward reaction progresses, some of the reactants will be converted into products, which leads to an increase in the concentration of the products.

Increasing Rate of Reverse Reaction

As the products' concentration increases, the likelihood of the reverse reaction occurring also increases. This is because there are now more product molecules available to collide with each other and convert back into reactants. As a result, the rate of the reverse reaction gradually speeds up.

Re-establishing Equilibrium

As the reverse reaction speeds up, the rate of the reverse reaction will eventually become equal to the rate of the forward reaction. When this occurs, the system reaches a new equilibrium state. This is why the rate of the reverse reaction gradually increases once a chemical reaction begins.

Unlock Step-by-Step Solutions & Ace Your Exams!

Full Textbook Solutions
Get detailed explanations and key concepts
Unlimited Al creation
Al flashcards, explanations, exams and more...
Ads-free access
To over 500 millions flashcards
Money-back guarantee
We refund you if you fail your exam.

Start your free trial

Over 30 million students worldwide already upgrade their learning with Vaia!

Recommended explanations on Chemistry Textbooks

View all explanations

What do you think about this solution?

We value your feedback to improve our textbook solutions.

Once a reaction begins, the rate of the reverse reaction gradually speeds up. Explain why this is so.

Short Answer

Step by step solution

Introduction to Chemical Equilibria and Reaction Rates

Le Chatelier's Principle

Initial Reaction Rates

Increasing Rate of Reverse Reaction

Re-establishing Equilibrium

One App. One Place for Learning.

Most popular questions from this chapter

Recommended explanations on Chemistry Textbooks

Ionic and Molecular Compounds

Chemical Analysis

Making Measurements

Chemical Reactions

Organic Chemistry

Chemistry Branches

Study anywhere. Anytime. Across all devices.