• Join over 1.2 million students every month
• Accelerate your learning by 29%
• Unlimited access from just £6.99 per month
Page
1. 1
1
2. 2
2
3. 3
3
4. 4
4
5. 5
5
6. 6
6
7. 7
7
8. 8
8
9. 9
9
10. 10
10
11. 11
11
12. 12
12

# detremining the rate equation

Extracts from this document...

Introduction

The determination of a rate equation Aim The aim of this experiment is to plan an experimental procedure leading to a graphical method to determine how the concentration or the volume of the components affects the rate of the reaction whose equation is given below: 2HCl(aq) + Na2S2O3(aq) --> 2NaCl(aq) + SO2(g) + S(s) + H2O(l) Introduction In this experiment in order for the reaction to take place the reactant particles must collide, and only some of those colliding particles lead to a chemical change. The rate of reaction is defined as the amount of in moles of a reactant which is used up in a given time, in this case it's the amount of sulphur formed in a given time. To work out the rate equation I will conduct two methods. In order to relate the rate of reaction with the concentration of the components involved I will have to obtain results to help me determine the rate of expression of the reaction. There are two methods used to determine the rate expression. This is done by measuring the concentration over time. The concentration has to be measured throughout the reaction. From the results obtained graphs are drawn and from that the order of the reaction is determined. The reason I'm not using this method is I don't have the right equipment to do that. The concentrations will be constantly changing and therefore making it harder to keep track of and record. Therefore I'm going to use the other method. The method I will use to determine the order of the reaction is initial-rate method. This method is used when the initial concentrations of the reactants that are going to be mixed together in the reaction flask, from this the initial rate of the reaction can be found. From my experiment I will obtain the time taken for the reaction to take place, from that I will work out the rate of the reaction and plot graphs of rate against concentration. ...read more.

Middle

Conclusion

It was hard to decide when to start the stopwatch and when to stop it. I t was very hard to judge whether the cross disappeared or not. As the solution started to get cloudy and the cross was about to disappeared there was at least a 5 second gap where the solution will be at the same intensity and this lead to the most significant error. Where you would be unsure whether the reaction has come to completion or not. In order to draw the graph the rate had to be worked out, dividing one by the time taken and if the timing error was around 5second this will be a major different in the value obtained and this will lead in anomalous results. So in the future to avoid this significant error I would use a colorimeter. I can also use a light sensor which more suitable for this type of experiment. This will measure the amount of light passing through the solution. The light sensor will have a fix point when to stop the timing. It will stop timing when the there is no light passing through the solution. And this will result in a more accurate and reliable results. If a calorimeter was used it would measure the amount of light adsorbed by the solution. An appropriate filter would be used allow only certain colour though. As the solution gets cloudy and starts to change colour the amount of light absorbed by the solution will also increase. When all the light is absorbed by the solution the timing should stop. To make this more accurate I will link the colorimeter to a data logger which is in turn linked to a computer where accurate timing will be recorded. I can also stir the solution to help me obtain more reliable results. This will enable all the particles to interact with each other. To get the most out of this method will have use a machine that will stir all the solutions at the same speed. ...read more.

The above preview is unformatted text

This student written piece of work is one of many that can be found in our AS and A Level Physical Chemistry section.

## Found what you're looking for?

• Start learning 29% faster today
• 150,000+ documents available
• Just £6.99 a month

Not the one? Search for your essay title...
• Join over 1.2 million students every month
• Accelerate your learning by 29%
• Unlimited access from just £6.99 per month

# Related AS and A Level Physical Chemistry essays

1. ## Investigating how concentration affects rate of reaction

This means that the temperature of an equation must always be known when working out the rate of reaction. Several different things contribute to a change in rate of reaction which concerned in my experiment: * Concentration * Temperature * Collision Frequency * Activation Enthalpy The Collision Theory can account

2. ## Experiment. Is the order of reaction affected if the acid is monoprotic or diprotic?

water bath to keep the temperature constant. However I will also need to change the concentration of the acids inorder to slow down the reaction. The next concentration that I will do a trial on is 0.5 mol dm-3. After I calculated the mass of magnesium that I will use, I carried out the experiment along with the modifications.

1. ## The Determination of rate equation

Zero order = the rate does not depend upon the concentration of the reactant. The rate of reaction is fixed. Doubling or tripling the concentration of the reactant makes no difference to the rate. Thus: Rate of reaction = k or rate of reaction = k[A]0.

2. ## Describe the construction, operation and application of distillation equipment used in industry

This in turn will keep a higher efficiency, while lowering both the operational costs and problems. Plate columns: can suffer badly from foaming. The foam produced is very thick and although it doesn't last very long it can lead to major operational problems.

1. ## Investigating the Rate of the Reaction between Bromide and Bromate Ions in Acid Solution

where k is the rate constant for the reaction. The overall order of the reaction is the sum of the orders of reaction of the separate reactants, so reaction is (x+y)th order overall. Similarly to the orders of reaction, the value of the rate constant can only be found by experiment.

2. ## Counting cells using the pour plate method

E.coli or sample of pasteurised milk * Supply of suitable agar medium, molten, kept in water bath at 45�C * Bunsen burner * China graph pencil or spirit marker pen * Discard jar containing disinfectant * Incubator at 30�C * Adhesive tape * Alcohol * Ruler The different items must

1. ## Science Investigation: HCL &amp;amp; Sodium Thiosulphate

reaction approximately 1 minute faster. This is due to the Particle Theory. The higher the concentration of sodium thiosulphate, the more particles there are in the solution, which also means there are more particles for the Hydrochloric Acid particles to collide with, creating more energy thus a faster reaction.

2. ## Individual investigation - Reaction to be studied Rate of reaction between propanone and ...

Methods: Steps used in "colorimetric": 1. I have to choose the appropriate filter and zero the colorimeter using the tube (test tube) of distilled water. 2. Using the pipette (2 cm3), measure 2 cm3 of propanone solution into the boiling tube. 3. Mix the required volume of I2 solution, HCL and H2O into 2nd boiling tube.

• Over 160,000 pieces
of student written work
• Annotated by
experienced teachers
• Ideas and feedback to
improve your own work