Topic Three (1.3): Rate Equation and Mechanisms

Introduction Icon.png Introduction

In this section the practical information gained from the knowledge of the rate equation is used to predict a reaction pathway or mechanism. This is applied to the alkaline hydrolysis of halogenoalkanes which occurs by two different mechanisms dependant on the structure of the reactant.

Read Icon.png Reading

Edexcel AS/A Level Chemistry Student Book 2 pages 15 to 18

Make Notes Icon.png Tasks

Complete the following:

  • Read pages 15 to 16 and take notes.

WATCH – The Rate Determining (Limiting) Step (YouTube) Links to an external site.

WATCH – Physical Chemistry - The Rate Determining Step (MASSOLIT) Links to an external site.

WATCH – Reactions of Halogenoalkanes (YouTube) Links to an external site.

Experiments Icon.png Practical Knowledge

  • Use Green Box CP9A (pages 17 to 18) to support the practical exercise below.

Download REVIEW & COMPLETE – CORE PRACTICAL 9A: Iodine Propanone Reaction

Download CHECK - Core Practical 9A Answers

  • Further questions on this practical exercise can be found on page 22 of the student guide.

Make Notes Icon.png Tasks

Complete the following:

  • Complete the ‘checkpoint’ questions.

Top Tip Icon.png Top Tips

Make sure that you understand the following key points:

  • When describing mechanisms show reactants and intermediates as structure formula or full display. This is much easier to follow.