• Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

Investigating the Factors Affecting the Rate of Reaction for the Iodine Clock

Extracts from this document...

Introduction

Science Coursework: Investigating the Factors Affecting the Rate of Reaction for the Iodine Clock Contents Introduction Scientific Theory Strategy (Plan) Results Analysis Evaluation References Introduction I am going to investigate how reaction rates in the iodine clock are affected. To do this I will consider the four possible independent variables: concentration, surface area, temperature and catalysts. I will then choose one factor and carry out a number of experiments, only changing that variable, and record the reaction speed. This will show how the reaction speed differs when the variable is altered. I predict that as the concentration of the Hydrogen Peroxide increases, the reaction rate will decrease. I think this because if there are more hydrogen peroxide particles to react with the other particles, the reaction will happen sooner. Theory The theory of the experiment is partly explained by the collision theory. The reaction can only take place when particles collide with enough energy. If there is not enough energy the reaction will not happen and the particle will bounce away again. The rate of a reaction depends on the number of successful collisions in a given amount of time. ...read more.

Middle

Using a burette, measure out the following amounts: * 30ml Potassium Iodide * 5ml Sodium Thiosulphate * 10ml Sulphuric Acid * 10ml Starch 2. Pour the chemicals into a conical flask 3. Using a burette, measure 30ml of Hydrogen Peroxide and add this to the conical flask. 4. Use the stopwatch to time how long the solution takes to change colour. 5. Repeat the experiment using 25ml of Hydrogen Peroxide and 5ml of deionised water, 20ml of Hydrogen Peroxide and 10ml of deionised water, 15ml of Hydrogen Peroxide and 15ml of deionised water and 10ml of Hydrogen peroxide and 20ml of deionised water. Repeat each experiment three times. Results Time of Reaction in Seconds Concentration of Hydrogen Peroxide (m) Test 1 Test 2 Test 3 Mean 0.1 326 24 23 23.5 0.083 36 36 34 35.3 0.067 42 40 41 41 0.05 60 (went yellow) 60 57 59 0.03 87 83 86 85.3 The first experiment contains an outlier because I was using a different hydrogen peroxide solution with a significantly lower molarity. This led to the time being much longer than the other results so I will discount this result from all averages. ...read more.

Conclusion

My results were very consistent and showed what I expected, so they are likely to be accurate, meaning my conclusions are likely to be accurate. I had one outlier, which was because I used a different hydrogen peroxide solution. I didn't have any other outliers which suggests the method and apparatus was accurate. However in one experiment it turned yellow, instead of the purple colour that occurred in every other experiment. I don't know why this was, but it is possible that I included the wrong amount of one of the chemicals. As the time was similar to the times recorded in the other experiments, I still included this in my results. Another way in which I could have improved my investigation would have been to investigate more than one factor and then compare the results. The title of the investigation was "Investigating the Factors Affecting the Rate of Reaction for the Iodine Clock" so by considering more than one variable I could have investigated this further. I would still have been unable to investigate surface area or catalysts but I could have carried out similar experiments to the ones I did, altering the temperature each time. This way I could have seen if the temperature affects the reaction more or less than the concentration. ...read more.

The above preview is unformatted text

This student written piece of work is one of many that can be found in our GCSE Patterns of Behaviour 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

See related essaysSee related essays

Related GCSE Patterns of Behaviour essays

  1. Rates of Reaction - The Iodine Clock

    [A] Doubling the concentration of reactant B quadruples the rate ?second order w.r.t. [B] The rate equation for this reaction can therefore be written as: Rate of Reaction ? [A]1[B]2 = k [A] [B] 2 The overall order would be equal to three.

  2. A-Level Investigation - Rates of Reaction – The Iodine Clock

    The order with respect to a particular reagent is known as a singular order, however, the overall order of a reaction is found by adding together all the singular order involved. E.g. In the reaction A + B --> C Doubling the concentration of reactant A doubles the rate ?First order w.r.t.

  1. Investigation Into the Factors Affecting Rate of Reaction

    This will be around 250cm� also. Thermometer- This will be used to keep the temperature constant. It will probably go up to 100 degrees centigrade as the heat produced will not be more than that. Distilled Water- This will be used to clean the apparatus and to mix the hydrochloric acid with to obtain my separate concentrations.

  2. Factors Affecting Enzyme Activity

    I will then record the amount of gas collected in the gas cylinder at ten second intervals for a period of two minutes. I will then repeat each experiment three times for each concentration of liver. I will record all my results on the table below.

  1. Find out how the rate of hydrolysis of an organic halogen compound depends on ...

    The concentrations used were 2 cm3, 4cm3, 6 cm3 and 8 cm3. A rate graph of the results is shown on page 25. Experiment 2 - altering the concentration of 2-bromo-2-methylpropane Before the experiment commenced, the conductivity meter was set up and calibrated, following the steps under 'Operation' and 'Calibration' in the conductivity meter leaflet on page 19.

  2. The Iodine Clock

    Potassium Iodide (cm3) Sodium Thiosulphate (cm3) Ammonium Persulphate (cm3) Water (cm3) Startch (cm3) Total Volume (cm3) Time (s) 5 3 5 11 1 25 334 10 3 5 6 1 25 145 5 6 5 8 1 25 451 5 3 10 6 1 25 133 These results show how

  1. Investigate the factors affecting the rate of a reaction.

    I also will record these results also. Since these numbers will be small and quite complicated I am going to add a further column to my final table of results and record the answers in standard form. After doing this I will have a complete set of results ready for analyzing and comparing.

  2. Factors Affecting the Rate of Catalytic Decomposition of Hydrogen Peroxide.

    the mass reached a constant value too quickly. The same was true when 10cm3 was used, and so 25cm3 was settled on as an appropriate value for volume of H202 to be used in the main investigation, as it gave a good spread of results and the constant mass was not reached too soon even with the higher concentrations used.

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