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

My aim is to plan and carry out an experiment to investigate how the concentration or temperature of sodium thiosulphate solution affects the rate of reaction when being reacted with dilute hydrochloric acid.

Extracts from this document...

Introduction

Planning INTRODUCTION My aim is to plan and carry out an experiment to investigate how the concentration or temperature of sodium thiosulphate solution affects the rate of reaction when being reacted with dilute hydrochloric acid. I want to find out whether changing the concentration or temperature of the reactant (sodium thiosulphate) affects the speed of the reaction. The reaction I am going to carry out is: Na2S2O3 + 2HCl --> 2NaCl + SO2 + H2O + S Sodium Thiosulphate + Hydrochloric Acid --> Sodium Chloride + Sulphur Dioxide + Water + Sulphur The rate of reaction is the speed at which the reaction takes place. It is measured by dividing 1 by the reaction time (rate 1/reaction time). The unit for the reaction rate is s-1. The aim of the experiment is simply to see how this rate changes. FAIR TEST (VARIABLE 1) It is always important when carrying out an experiment to keep it fair. This means that what you are investigating is the only thing that does affect the experiment. For example, in this experiment when I investigate the effect of changing the concentration, all other variables must stay constant to keep the experiment fair. I must keep the total volumes of both the hydrochloric acid and the sodium thiosulphate equal. I am going to use 10cm3 of hydrochloric acid throughout for every reaction. ...read more.

Middle

MAIN EXPERIMENT (VARIABLE 1) APPARATUS: * Safety Glasses * Conical Flask * Burette * Stopwatch * Piece of Paper (for measuring when reaction is completed) * Dilute Hydrochloric Acid * Solution of Sodium Thiosulphate * Retort Stand and Clamp * Water PREDICTION (VARIABLE 2) I believe that as I increase the temperature of sodium thiosulphate and hydrochloric acid, the rate of reaction will increase. In liquids the particles are constantly moving and so constantly colliding with each other. They will normally always react when they collide with enough energy. The minimum amount of energy needed in a collision for the particles involved to react is called the Activation Energy. It is needed to break the bonds. If the particles collide with insufficient energy, the particles simply bounce off each other. If every collision occurred with energy, at least that of the activation energy, then the reaction would be extremely fast. As you increase the temperature, the reactant particles gain more kinetic energy and start to move faster. This means that there is a greater chance of collisions between the particles, since they are moving about quicker in the same volume of solution. Also a greater proportion of the particles acquire the activation energy as you increase the temperature, so more particles are able to collide and definitely react. ...read more.

Conclusion

IMPROVEMENTS There are improvements I could make to my experiment which would give even more accurate results. I could: * Take more results by doing more concentrations and more repetitions. The more I do, the more accurate my results become, but I wouldn't be able to do lots more because there is a time limit to this experiment. * Take the results to more decimal places, since this would make my graph more accurate. However, if I do lots of decimal places it would be difficult to plot these on a graph of reasonable size. * Put the conical flask in a water bath, to keep the temperature constant. The one other variable apart from concentration which can affect the rate of reaction of solutions is temperature. I did the experiment at room temperature which is about constant. However, to make the experiment even more accurate I could put each conical flask in a water bath before I add the two solutions to each other. I could put the conical flask in a water bath at around 20�C, and I would do this before each reaction to make sure it stays constant. It must be 20�C every time so that the temperature is constant, and I know that temperature is not affecting the rate of reaction. ...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. Experiment to Investigate the Rate of Reaction between Hydrochloric Acid and Sodium Thiosulphate, with ...

    The person using the stopwatch and timing the rate of reaction must be kept the same throughout the whole experiment so that the results are more precise. This is because if different people are used for the timing, they will time with a different accuracy and precision, so it is

  2. How Concentration affects the rate of reaction.

    For a reaction to happen a certain amount of energy is needed to make reactants bond called the activation energy. If the particles have enough energy when combined to overcome the activation energy "barrier" and are correctly orientated then a reaction occurs and a new product is formed.

  1. Factors Affecting the Rate of Reaction between Hydrochloric Acid and Sodium Thiosulphate.

    If some acid had been misplaced into the sodium thiosulphate then the reaction would have already started, and this would mean my results for experiment 2 to be slightly quicker. This seems to relate to my data and because of test 2 results being too quick the line of best fit may be slightly out.

  2. Experiment to investigate how changing the concentration of hydrochloric acid affects the rate of ...

    Experiment 2: 1. Display 1 beaker and place 2g of chalk in it. Pour 40ml of hydrochloric acid in the beaker and observe: * If it is an endothermic or exothermic reaction * What happens to the chalk * What do I see * Rate of reaction Observation and results Reactant Is the reaction endothermic or exothermic?

  1. Design an experiment to investigate the effect of varying the temperature of Sodium Thiosulphate ...

    The results from the preliminary experiment are shown in the table below showing 'the effect of concentration on reaction time' S.T (ml) Water (ml) Conc. (g/l) % Conc. Acid (ml)

  2. Investigating rates of reaction between hydrochloric acid and sodium thiosulphate and how heat/ temperature ...

    My prediction was that if you increase the temperature of a reaction, you decrease the time it takes to occur. From looking at my results, I can see that this hypothesis was correct as the time for the cross to disappear decreased as the temperature rose.

  1. Sodium thiosulphate and hydrochloric acid Investigating how the rate of reaction is affected ...

    requirement stated in the collision theory that are: To react particles must collide with enough energy to break existing bonds and with the correct orientation to bring reactive sites close together. Bringing the reactive sites closer together means that the likelihood of a reaction occurring is increased so in a

  2. Measuring the rate of reaction, when dilute sodium thiosulphate solution and dilute hydrochloric acid ...

    Time for the "X" to disappear (secs) 1 2 3 5 25 0 37 41 38 5 20 5 30 35 36 5 15 10 42 59 55 5 10 15 1.22m 1.25m 1.31m 5 5 20 5.10m 4.58m 4.40m I got these results by following a method that the teacher gave us.

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