Log out Go to App
Go to App

Learning Materials

Features

Discover

Chapter 17: Problem 4

Explain what half-reactions are and why they are useful.

Short Answer

Expert verified
Half-reactions are the separated oxidation and reduction parts of a redox reaction, representing electron loss and gain respectively. They are useful for balancing redox reactions, understanding electron transfer, predicting and controlling chemical reactions, and applications in various chemical disciplines like electrochemistry and biochemistry.

Step by step solution

01

Understanding Half-Reactions

Half-reactions are simply the two parts of a redox (oxidation-reduction) reaction. One half-reaction represents oxidation, where a substance loses electrons, and the other half-reaction represents reduction, where a substance gains electrons. In an oxidation half-reaction, the substance that donates the electrons becomes oxidized, while in a reduction half-reaction, the substance that receives the electrons is reduced.
02

Balancing Redox Reactions using Half-Reactions

One common and important use of half-reactions is in balancing redox reactions. A redox reaction is balanced by ensuring the total number of electrons lost in the oxidation half-reaction is equal to the total number of electrons gained in the reduction half-reaction, thus ensuring charge conservation. This process is also known as 'electron bookkeeping'.
03

Understanding Importance of Half-Reactions

Half-reactions play a crucial role in understanding how electrons are transferred from one substance to another in a redox reaction. They provide information about the substances that are oxidized and reduced, including how many electrons are involved in the reaction. This understanding is fundamental to many areas of chemistry, such as electrochemistry and energy production in cells. Half-reactions are also essential for predicting and controlling chemical reactions.

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!

Key Concepts

These are the key concepts you need to understand to accurately answer the question.

Oxidation and Reduction
When delving into the world of redox reactions, it's essential to grasp the twin concepts of oxidation and reduction. These processes occur simultaneously and are connected through the transfer of electrons. Oxidation refers to the loss of electrons by an atom or molecule; when an entity loses electrons, it is said to be oxidized. On the other hand, reduction is the gain of electrons. An atom or molecule that gains electrons is hence reduced. Remember the mnemonic 'OIL RIG': Oxidation Is Loss, Reduction Is Gain.

Balancing Redox Reactions
The balancing of redox reactions is a fundamental skill in chemistry to ensure that the number of electrons lost and gained are equal. This reflects the principle of conservation of charge. To balance a redox reaction, split it into two half-reactions: one for oxidation, the other for reduction. Each half-reaction is balanced separately, first for mass (atoms) and then for charge (electrons). Once both half-reactions are balanced, they can be combined to give the overall balanced redox equation. This requires that the total charge and number of atoms of each element are equal on both sides of the equation.

Electron Transfer in Chemistry
Electron transfer is the crux of many chemical reactions, especially in redox reactions. It's the movement of electrons from one molecule (the reducing agent) to another (the oxidizing agent) that drives the chemical change. This electron movement is crucial not only in synthetic reactions but also in biological processes, like those occurring in cellular respiration, where energy is produced in the form of ATP. The manner of this transfer—sequential or simultaneous—affects the reaction mechanism and the rate at which the reaction proceeds.

Electrochemistry Fundamentals
Electrochemistry examines the interaction between electrical energy and chemical change, which is exemplified by redox reactions. Central to this branch of chemistry is the concept of half-reactions, which provide a deeper understanding of electrochemical cells, including batteries and fuel cells. In an electrochemical cell, the oxidation half-reaction occurs at the anode, while the reduction half-reaction takes place at the cathode. By analyzing half-reactions, we can predict voltage, power output, and the feasibility of electrochemical processes.

One App. One Place for Learning.

All the tools & learning materials you need for study success - in one app.

Get started for free

Most popular questions from this chapter

What is electroplating?

Assign oxidation numbers to the atoms in the ion \(\mathrm{PF}_{6}^{-}(a q) .\)

Assign an oxidation number to the \(\mathrm{N}\) atom: in each of the following oxides of nitrogen: \(\mathrm{N}_{2} \mathrm{O}, \mathrm{NO}, \mathrm{NO}_{2}, \mathrm{N}_{2} \mathrm{O}_{3}, \mathrm{N}_{2} \mathrm{O}_{4},\) and \(\mathrm{N}_{2} \mathrm{O}_{5} .\)

In an electrochemical cell, what role does the porous barrier play? What would happen without it?

Suggest how the word oxidation might have come to be the general term for a loss of electrons.
See all solutions

Recommended explanations on Chemistry Textbooks

The Earths Atmosphere

Read Explanation

Making Measurements

Read Explanation

Kinetics

Read Explanation

Chemical Reactions

Read Explanation

Chemistry Branches

Read Explanation

Organic Chemistry

Read Explanation
View all explanations

What do you think about this solution?

We value your feedback to improve our textbook solutions.

Study anywhere. Anytime. Across all devices.

Sign-up for free