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

Investigate the principal factors that affect the rate of reaction between Sodium Thiosulphate and hydrochloric acid.

Extracts from this document...


Rates Of Reaction Coursework Aim: To investigate the principal factors that affect the rate of reaction between Sodium Thiosulphate and hydrochloric acid. Theory: The reaction between sodium thiosulphate solution and dilute hydrochloric acid: HCl+sodium thiosulphatesodium chloride+sulphur dioxide+sulphur+water. HCl(aq) + Na2S2O3(aq) NaCl(aq) + SO2(g) + S(s) + H2O(l) The sulphur formed in this reaction makes the colourless solution go cloudy. The reaction is usually carried out in a flask placed on a piece of white paper which has a black cross on it. At the beginning of the reaction, the cross can be seen easily. As the flask becomes more and more cloudy, the cross gets harder to see. Factors which affect the rate of reaction: * Increasing the temperature of a reaction increases the rate of a reaction. At the higher temperatures reactant particles move faster and collide more often and more violently. For every 10?c rise in temperature, the rate of reaction doubles. * Increasing the concentration of reactants increases the rate of a reaction. This is because there are more particles in the same volume so more collisions are possible every second. ...read more.


Although my results did not completely satisfy this statement, there is some evidence to prove it. At high temperatures, the rate of reaction is very rapid; therefore the time for the reaction to take place is quite small. If you lowered the temperature by 10?c you would expect the time for the reaction to double (20 secs for 50?c, 40 secs for 40?c). My results were very similar to these model results but not always exact. The theory that the rate of reaction doubles for every 10?c rise in temperature always gives a curved graph, it will never be a straight line. My graphs for temperature versus time show this very well. My other prediction was that increasing the concentration of the reactants would increase the rate of reaction. My results agree with this prediction. Concentrated sodium thiosulphate reacted a lot faster than dilute sodium thiosulphate. The results go down fairly steadily on the graph but the 25cm? result could be an anomalous result. This result could be correct. The line of best fit is wrong as it says that the solution will go cloudy in 209 seconds when there is no sodium thiosulphate present. ...read more.


This caused a drop in temperature when the sodium thiosulphate and acid were mixed. This is not important as it is a systematic error (it happened every time and made the temperature drop by the same amount). This could explain the reason why the rate of reaction did not always double for every 10?c rise in temperature. The beakers used were washed before each experiment. There was no chance of contamination from other chemicals as they were all washed with sodium thiosulphate before hand. Future Investigations/Improvements: If I could do the experiment again, I would make a few changes. These changes would give more accurate and also a wider range of results. I would use a magnetic stirrer as opposed to hand if possible. The magnetic stirrer can be set to a certain speed and remains at that speed for the whole experiment. I would use light sensors to decide exactly when the reaction had reached the completion point, as they are far more accurate than the eye. I would repeat each experiment at least 3 times to ensure that the results are accurate. I would heat the acid as well as the sodium thiosulphate when investigating temperature. This would mean that the acid wouldn't cool down or heat up the solution. ...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. The aim of this coursework is to investigate the rate of reaction between sodium ...

    As the experiment continues, the more yellow sulphur precipitate is formed, thus causing the solution to become opaque. Changing the concentration of a solution affects the rate of reaction. The concentration of a solution is how strong the solution is.

  2. To investigate the effect of varying the masses of white sugar and yeast and ...

    The measuring cylinder was placed vertically placed into a thermostatic water bath at 27oC with the water covering at least 3/4 of the measuring cylinder. The stopwatch was immediately started and the volume the dough had reached was recorded every minute for 15 minutes.

  1. Investigating the factors influencing the rate of reaction between Sodium Thiosulphate and Dilute Hydrochloric ...

    The temperature should be kept fixed because the higher the temperature, the faster the rate of reaction. This is due to the fact when a substance is heated the molecules gain kinetic energy. This consequently results in more collisions between the free moving particles in a solution, causing a reaction between them, which would alter the overall initial reaction rate.

  2. How does the Temperature affect the Rate of Reaction between Sodium Thiosulphate and Acid?

    The optimum concentration was the one that came out with the least percentage of error. The temperature ranges were from 20oC to 60oC. But for the trial experiments we just did room temperature (20oC) and 60oC as they are the two extremes and we know that for the other temperatures

  1. HCL and sodium thiosulphate - investigate which factors affect the rate of reaction.

    This means the particles around in the solution will have more area to work on so there'll be more useful collisions. A catalyst works by giving the reacting particles a surface to stick to where they can bump into each other.

  2. Investigating what factors affect the rate of reaction Of sodium thiosulphate and hydrochloric acid.

    Test No. Hydrochloric acid (ml) Sodium thiosulphate (ml) Water (ml) Sodium thiosulphate (%) Water (%) 1 5 50 0 100 0 2 5 40 10 80 20 3 5 30 20 60 40 4 5 20 30 40 60 5 5 10 40 20 80 This experiment will be done twice with the above measurements

  1. How does the Temperature affect the rate of the reaction between Sodium Thiosulphate and ...

    When two liquids of different temperatures are mixed together the solution produced will have a new resultant temperature. The formula used to tell us what this resultant temperature will be is: V1T 1 + V2T2 V1 + V2 T3 =Resultant Temperature This formula can be rearranged so that the temperature

  2. I aim to investigate the affect of temperature on the rate of reaction between ...

    In this experiment we are only interested in temperature. Where temperature is not high enough to provide energy for the particles to move at a high enough speed, the particles will just not react. Basically, not as many particles will be able to react together in a certain amount of time.

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