Redox Reactions Notes: Class 11 Chemistry Chapter 7
Class 11 Chemistry Chapter 7 Redox Reactions covers the classical and electronic concepts of oxidation-reduction, oxidation number rules, balancing redox equations, and redox reactions as the basis of titrations.
Overview of Topics & Subtopics (Click to Jump)
1. Classical and Electronic Concepts of Redox Reactions
Short Note:
• Oxidation: loss of electrons (or addition of oxygen/removal of hydrogen); Reduction: gain of electrons (or addition of hydrogen/removal of oxygen).
• A redox reaction involves both oxidation and reduction occurring simultaneously, with electrons transferred from the reducing agent to the oxidising agent.
2. Oxidation Number
Short Note:
• The oxidation number of an atom is the charge it would have if the compound were composed of ions, assigned according to a set of rules (e.g., oxidation number of an element in its free state is 0; of oxygen is usually −2; of hydrogen is usually +1).
• Oxidation is characterised by an increase in oxidation number; reduction by a decrease in oxidation number.
3. Balancing Redox Reactions
Short Note:
• Oxidation Number Method and Half-Reaction (Ion-Electron) Method are the two standard techniques used to balance redox equations, especially in acidic or basic medium.
4. Redox Reactions in Titrations
Short Note:
• Redox titrations, such as those involving KMnO4 or K2Cr2O7 as oxidising agents, are used to estimate the concentration of reducing agents in a solution based on the stoichiometry of electron transfer.