• 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
  13. 13
    13
  14. 14
    14
  15. 15
    15

Factors that affect the rate of reaction.

Extracts from this document...

Introduction

Factors that affect the rate of reaction Background We can measure the rate of reaction by measuring the rate of change by either, - one of the reactants disappearing with time - one of the product forming with time. A chemical reaction can only occur between particles when they collide (hit each other). Particles may be atoms, ions or molecules. There is a minimum amount of energy which colliding particles need in order to react with each other. If the colliding particles have less then this minimum energy, then they just bounce off each other and no reaction occurs. This minimum is called the minimum energy. Collision Theory: - particles must collide - with sufficient energy to break existing bonds - with the correct orientation Measuring rates: We can measure how quickly products form or we can also measure how quickly reactants are used up. Here are some graphs which you can get whilst studying these two different methods, Factors that affect the rate of reaction: 1.Raising the temperature has the same effect on all three reactions. Raising the temperature makes the particles move faster. This means that more particles collide with each other per second. The rate of the reaction increases. Also, the faster the particles are travelling, the greater is the proportion of them which will have the required minimum energy for reaction to occur. As a general guide, raising the temperature of a reaction by 10 �C will double the rate of the reaction. The gradient of the plot will be twice as steep. Here is a prediction graph for an experiment investigating the effect of temperature on the rate of a reaction: 2.Increasing the concentration (in solution). Increasing the concentration of a substance in solution means that there will be more particles per dm3 of that substance. The more particles that there are, the more will collide per second, and so the rate of the reaction increases. ...read more.

Middle

Time taken for cross to disappear (secs) Rate of the reaction (/s) 1 40 32 0.031 1 4 321 0.003 2 40 19 0.053 2 4 242 0.004 0.5 40 40 0.025 0.5 4 773 0.001 Conclusion: I am going to use the 2 Molar acid in my main experiment. This is because it had the fastest results, where as the 0.5 Molar acid had results which took too long (776 secs). If I used this in my final experiment then I would not have enough time to collect sufficient evidence to support my case. Final Experiment Safety: To make sure that I, and people around me are safe whilst I am carrying out my experiment, I will remember the following points, - I will remember to wear goggles to protect my eyes - I will remember to wear a lab coat to protect my clothes and skin - I will tuck my stool out of the way, so no one can trip over it. - I will make sure my bag is tucked away, so no one could trip over it - I will not rush about or run, resulting in knocking something or someone over - I will stand up whilst doing my experiment, so that just in case something spills, I will be able to get away fast - I will not leave the apparatus at the side of the table, so it cannot get knocked over - I will wear my hair up Here is some safety information about hydrochloric acid and sodium thiosulphate which I will be handling during the experiment. Hydrochloric acid: Corrosive: may cause burns. The vapur is very irritating to the respiratory system. Solutions equal to and greater then 6.5 M are corrosive and those equal to and greater than 2 M but less then 6.5 are irritant. It could be deemed sensible to label 1 M solutions as irritant as well. ...read more.

Conclusion

Also, I could of started the stop-clock slightly after or before I actually should of. The information that I collected could be adequate to support my conclusion fully, I could of however collected more evidence by doing more repeats and maybe doing more different molars of acid and concentrations of thiosulphate. By collecting more evidence, I would of had a wider range of information from which to make an average out of. Also I would of repeated all of the anomalies that I acquired, resulting in a more accurate average. If I had, had more time. I do feel that the method that I used was suitable for my experiment. If I could of, I could of used a light sensor and data logging to investigate in more accurate detail. The light sensor detects the amount of light that travels through the reaction mixture in the beaker. As the mixture gets cloudier the amount of light reaching the light sensor decreases. This would of acquired much more accurate results, as it uses digital readings to get the results. To extend my experiment I could of investigated another factor that affects the rate of reaction, for example, the effect of temperature on a reaction rate. Here is the method that I would of followed: - Put 10cm3 of sodium thiosulphate solution and 40cm3 of water into a flask. - Measure out 5cm3 of dilute hydrochloric acid in a small cylinder. - Warm the thiosulphate solution in the flask if necessary, to bring it to the required temperature. (I would do this experiment five times, with temperatures in the range 15-65 degrees Celsius.) - Add the acid from the cylinder and start the clock. Swirl the flask to mix the solutions and place it on a piece of white paper marked with a cross - Look down at the cross from above. When the cross disappears. Stop the clock and note the time taken. Record the temperature of the mixture in the flask. ...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. How does temperature affect the rate of reaction between sodium thiosulphate and hydrochloric acid?

    Otherwise it would have a different intensity, and might become easier or harder to obscure. A pair of goggles will be worn during the heating part of the experiment in order to protect the eyes. An overall will also be worn to protect the skin and clothing.

  2. Free essay

    Investigating the Rate of Reaction - Sodium Thiosulphate and Hydrochloric Acid

    It may be affected by the concentration of reactants, temperature of reactants and the company of a catalyst. The increase of a concentration means there are more collisions and successful collisions. Therefore, the rate of the collision increases. The time it takes for a change to happen can be measured

  1. The reaction between Sodium Thiosulphate and Hydrochloric Acid.

    I have chosen 40�C because the molecules will be moving quickly enough to make the reaction happen at a fast rate, but they won't be moving too quickly so that the reaction happens too fast. The very low concentrations of hydrochloric acid may take a very long time to complete

  2. Measuring the reaction rate of sodium thiosulphate in hydrochloric acid

    Instead, we were given a wide range of equipment from which to choose the things we needed and told to use our preliminary experiments to choose the best suited equipment for the task. This included the choice between beakers and conical flasks in three different sizes as a container and different sizes of measuring cylinders.

  1. Free essay

    Close Your Eyes

    She didn't look confident at all. More like a rabbit caught in the headlights. Of course she wasn't confident. She was new, she didn't know her way around and she didn't know anyone that she could ask. I could see her glancing around at everyone.

  2. How does the concentration of sodium thiosulphate solution affect the rate of its reaction ...

    --> 1NaCl (aq) + H2O + SO2 (aq) + S (s) The reactants begin as clear liquids. During the experiment sulphur is produced. This makes the clear reactants turn cloudy until the reactants become opaque. This is how I am going to measure the amount of time the different concentrations take to react.

  1. How Does The Concentration Of Sodium Thiosulfate Affect The Rate Of This Reaction?

    Only a small per cent result in a reaction. This is due to the energy barrier to overcome. Only particles with enough energy to overcome the barrier will react after colliding. The minimum energy that a particle must have to overcome the barrier is called the activation energy, or Ea.

  2. Effects of Concentration of Sodium Thiosulphate in the reaction of Hydrochloric Acid and Sodium ...

    Rate 1/t (s-1) 30.5 0.0328 39 0.0256 56 0.0179 94 0.0106 251.5 0.00398 Table showing Time and Rate As is shown in the table above, when the time increases the rate increases so therefore they are inversely proportional. To prove this I will take two sets of results.

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