Year 1 Organic Chemistry Mechanisms Explained | Ultimate AS & A-Level Chemistry Guide

Introduction to major mechanisms in year one chemistry, including electrophilic addition, nucleophilic substitution, and elimination. Explanation on drawing mechanisms and using curly arrows to represent bond movements.

Explanation and demonstration of electrophilic addition mechanism using the example of hydrogen bromide reacting with an alkene. Detailed breakdown of the steps involved in the mechanism and the formation of the organic product.

Demonstration of the electrophilic addition mechanism with Br2 reacting with an alkene. Description of the mechanism steps and the formation of the organic product, one-two dibromoethane.

Explanation of drawing mechanisms for reactions of unsymmetrical alkenes with hydrogen bromide. Illustration of major and minor products formed based on the mechanism.

Discussion on carbocation stability and its influence on the major product formed in electrophilic addition reactions. Explanation using energy profile diagrams.

Explanation and demonstration of nucleophilic substitution mechanism using the example of halogenoalkane reacting with cyanide ion as a nucleophile. Detailed steps and product formation.

Description of nucleophilic substitution mechanism with ammonia as a nucleophile. Comparison with other nucleophiles and explanation of intermediate steps and product formation.

Explanation of multiple substitution in nucleophilic substitution reactions and the role of excess ammonia in promoting multiple substitutions. Discussion on adjusting conditions for different products.

Explanation and demonstration of elimination mechanism using hydroxide ion to remove a molecule from a halogenoalkane. Detailed steps and product formation in elimination reaction.

Illustration of elimination mechanism for symmetrical halogenoalkanes. Description of steps involved in the elimination process and product formation.

Discussion on alcohol dehydration and elimination mechanisms to form alkenes using concentrated hot sulfuric acid. Explanation of protonation of oxygen and formation of the alkene product.

Explanation of how different alkenes and isomers are produced in elimination reactions. Description of the isomeric products formed and their characteristics.