Free Essays, Term Papers, Research Papers at Anti Essays

THE EFFECT OF TEMPERATURE AND CONCENTRATION ON REACTION RATE

INTRODUCTION

FACTORS INFLUENCING REACTION RATE:

The study of chemical reactions is not complete without a consideration of the rates at which these reactions proceed. We know that some reactions such as those between ions in solution frequently proceed very rapidly, while others proceed so slowly that the rate is not even detectable. The practical importance of these rate considerations is difficult to exaggerate. For example, a metal which is exposed to weather will undergo reactions with oxygen and water which result in corrosion. The speed with which a certain reaction will proceed will often determine the industrial usefulness of the material.

Among the most important factors influencing the rate of a reaction are: temperature, concentration and catalysis. In addition, for solids the condition of the surface is of great importance.

There are two main theories involved in explaining reaction rates. These are the Activated Complex (Transition State) Theory and the Collision Theory. However, in the lecture part of the course, you will also look at the Activated Complex (Transition State) Theory.

COLLISION THEORY

Consider the simple reaction: A + B Products

A and B are atoms, ions, or molecules (we shall call them molecules in the discussion which follows) and may be
in the gas phase or in solution. In order for A and B to react with each other, they must come together. Since molecules are in rapid and continual motion, molecules of A and Be will collide with one another at frequent intervals. However, not every collision of A and B will result in the formation of products. Before a reaction can occur, the reactants collide with a certain amount of energy termed the activation energy. This energy comes from the kinetic energy that A and B possess, so that...