# A2 Kinetics

A guide to all the kinetics stuff with the exception of the rate determing step. Enjoy.

- Created by: Kelly Davies
- Created on: 27-03-14 13:39

First 368 words of the document:

Rate, kinetics and orders

What you SHOULD be able to do by the end of the section:

Define the terms: Rate of reaction, Rate constant (k), order of a reaction and the overall

order of a reaction.

Work out the order of a reaction bases on initial rate data.

Calculate K and its units from initial rate data.

Predict a change in K based on a change in conditions.

Important definitions:

Order: A number used to describe how a reaction rate is affected by the concentrations of a

certain product in a reaction.

Overall Order: The total of all the orders of all products added together. Example if A+B C

and A had an order of 3 and B had an order of 5 then the overall order would be 8 (5+3).

Rate of reaction: A term used to describe the change of the concentration of products

made over a set period of time.

Rate Constant: A number in a rate equation often known as K that is only changed when

temperature or pressure increases.

How to determine a reaction order

When it comes to determining order, you'll mainly have to worry about deducing your order based

on previous data, there are 2 ways of data presentation, you have to worry about:

1. Tabular (data is in a table)

2. Graphically (data is in a graph).

We'll firstly start with a tabular question as they like to be nice a frequent (bless them).

Let's say that we added chemical A and chemical C together to make chemical B. Our teacher then

decided to make use deduce the order of A and C in the experiments. So what do we do?

Experiment Concentration of A Concentration of C Initial Rate

1 1 x 10-3 1 x 10-3 1 x 10-3

2 1 x 10-3 0.5 x 10-3 0.25 x 10-3

3 4 x 10-3 2 x 10-3 16 x 10-3

Well at first glance this table might be horrible, icky and full of numbers however it is possible to

deduce the order of both A and C and thus deduce an overall order.

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