Lesson Notes By Weeks and Term v4 - SHS 2

Lesson Video

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Performance objectives

• Identify and name alkanoic acids up to C6.
• Describe how alkanoic acids are prepared.
• Explain the physical properties of alkanoic acids.
• Understand why alkanoic acids are acidic.

Lesson summary

Welcome, students! Today, we are exploring a very important family of organic compounds called alkanoic acids. You have already encountered one of them in your homes: the sharp-smelling liquid we call vinegar, which is used in cooking and preserving food like fish for *shito* or pickling vegetables. The main component in vinegar is ethanoic acid. This lesson will help us understand the structure of these compounds, how to name them, how they are made, their unique properties, and their many uses in Ghana and around the world, from preserving our food to making plastics and perfumes.

Lesson notes

A. What are Alkanoic Acids? Structure and Functional Group

Alkanoic acids (also known as carboxylic acids) are organic compounds that contain the carboxyl functional group. Functional Group: The carboxyl group consists of a carbonyl group (C=O) and a hydroxyl group (-OH) attached to the same carbon atom. Its formula is -COOH. General Formula: The general formula for a straight-chain alkanoic acid is CnH2n+1COOH, where n starts from 0 (for the first member). Or, R-COOH, where R is a hydrogen atom or an alkyl group. B. Homologous Series and IUPAC Nomenclature

The first six members of the alkanoic acid homologous series are:

| No. of Carbon Atoms | Molecular Formula | Condensed Structural Formula | IUPAC Name | Common Name | | :--- | :--- | :--- | :--- | :--- | | 1 | CH₂O₂ | HCOOH | Methanoic acid | Formic acid | | 2 | C₂H₄O₂ | CH₃COOH | Ethanoic acid | Acetic acid | | 3 | C₃H₆O₂ | CH₃CH₂COOH | Propanoic acid | Propionic acid | | 4 | C₄H₈O₂ | CH₃CH₂CH₂COOH | Butanoic acid | Butyric acid | | 5 | C₅H₁₀O₂ | CH₃(CH₂)₃COOH | Pentanoic acid | Valeric acid | | 6 | C₆H₁₂O₂ | CH₃(CH₂)₄COOH | Hexanoic acid | Caproic acid |

Evaluation guide

• Explain the structure, nomenclature, preparation, properties and uses of alkanoic
• acids as well as their characteristic test .
• Collaborative Learning Approach:
• Generate members of alkanoic acids (carboxylic acids) up to C6.