Реферат: Rate Of Reaction In Sodium Thiosulphate And

Effects of a temperature change – The graph below shows Maxwell-Boltzmann

distribution graphs for a fixed mass of gas at two temperatures ? T1 and T2,

where T2 is roughly 10°C higher than T1. The total area under the curve remains

the same, since there is no change in the number of particles present.

A small increase in temperature causes significant changes to the distribution

energies. At the higher temperature:

1. The peak is at a higher energy.

2. The peak is lower.

3. The peak is broader.

4. There is a large increase in the number of particles with higher energies.

It is the final change that results increase in rate, even with a relatively

small increase in temperature. A small increase in temperature greatly

increases the number of particles with energy greater than the activation

energy. The shaded areas on the energy distribution curves show this.

Effect of a catalyst – A catalyst works by providing an alternative reaction

pathway that has lower activation energy. A catalyst does not alter the

Maxwell-Boltzmann distribution. Because a catalyst provides a reaction route of

lower activation energy, however, a greater proportion of particles will have

energy greater than the activation energy.

Secondary Sources Used:

AS Level Chemistry Textbook (kinetics module)

The Internet

Dr. Jones?s Chemistry Lessons

Information sheets from Dr. Jones

Obtaining Evidence

Temp.(°C)???????? Time 1 (s)???????? Time 2 (s)??????? Average (s)

20??????????????????? 110.67????????????? 107.42????????????? 109.045

30??????????????????? 100.13????????????? 103.34????????????? 101.735

40??????????????????? 64.20?????????????? 65.92????? ??????????65.06