Question

Every redox reaction is made up of \(\ldots . .\) that which involves gain in clectrons is called ...... (1) Reduction half-reaction, two half-rcactions (2) Oxidation half-rcaction, two half-reactions (3) Two half-reactions, oxidation reaction (4) Two half-reactions, reduction reaction

Short answer

Option (1): Reduction half-reaction, two half-reactions.

Step-by-step solution

Understanding Redox Reactions

Redox reactions consist of two half-reactions: oxidation and reduction. Oxidation involves the loss of electrons, while reduction involves the gain of electrons.

Identifying the Components

The question asks about the process that involves the gain of electrons. This describes the reduction half-reaction within the redox reaction.

Matching with the Options

Compare each option to the identified components of a redox reaction. Option (1) correctly refers to the reduction half-reaction involving the gain of electrons and mentions two half-reactions.

Key concepts

Oxidation

In redox (reduction-oxidation) reactions, oxidation is one of the key processes involved. Oxidation refers to a chemical reaction in which a substance loses electrons. This increase in oxidation state means that the substance has been oxidized and typically becomes more positive. These reactions are crucial in fields ranging from chemistry and biology to industrial applications.

For example, when a piece of iron rusts, iron atoms lose electrons and form iron oxide. Here’s another way to remember: LEO (Lose Electrons = Oxidation). This mnemonic can assist in quick identification during your studies.

These reactions are highly important in processes like cellular respiration, where cells in the body utilize oxidation to produce energy.

Reduction

Reduction is the counterpart to oxidation in redox reactions. This process involves a substance gaining electrons, which decreases its oxidation state and typically makes it more negative. Reduction is just as crucial as oxidation in various chemical processes.

Remember the mnemonic GER (Gain Electrons = Reduction) to help you identify reduction quickly.

An example of reduction can be seen in photosynthesis, where carbon dioxide gains electrons to form glucose. The reduction process is vital in both biological systems and industrial applications like metal refining.

In redox reactions, for every oxidation event (where electrons are lost), there is a corresponding reduction event (where those same electrons are gained).

Half-Reactions

Every redox reaction can be broken down into two simpler parts called half-reactions. Each half-reaction represents either the oxidation or the reduction process and helps to explain the transfer of electrons in more detail.

In a redox reaction:

• The oxidation half-reaction shows the loss of electrons. Example: Mg → Mg²⁺ + 2e⁻
• The reduction half-reaction shows the gain of electrons. Example: O₂ + 4e⁻ → 2O²⁻

By writing out these half-reactions, you can easily balance redox equations, ensuring that the number of electrons lost in the oxidation half matches the number of electrons gained in the reduction half. Breaking down complex reactions in this way makes them easier to understand and manage. Each half-reaction provides a detailed picture of what happens to the involved species during the redox process.

Electrons

Electrons play a central role in redox reactions as they are the particles that are transferred between substances. Understanding the movement of electrons is key to grasping how these reactions work.

In every redox reaction, electrons are lost by one substance (oxidation) and gained by another (reduction). This transfer is what makes redox reactions so essential in various chemical and biological processes.

For instance, in an electrochemical cell, electrons move through an external circuit, providing electrical energy. In biological systems, electron transfers in redox reactions are critical for processes like ATP production during cellular respiration.

Visualizing electrons as tiny charged particles that can be transferred from one atom or molecule to another helps in understanding the basics of redox chemistry. By focusing on where the electrons are going, you can more easily identify if a substance is oxidized or reduced and understand the changes in chemical structure that occur.