• 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

In my investigation I am going to look at how concentration affects the rate of reaction, and the reaction I am going to look at is Sodium Thiosulphate (Na2 S2 O3) and Hydrochloric Acid (HCl).

Extracts from this document...

Introduction

An Investigation into the rate of reaction is affected by the concentration of a solution The rate of a reaction is the speed at which the reactants change into products. Reactions can be fast and slow for example rusting is a slow reaction and magnesium reacting with oxygen is an example of a fast reaction. There are several factors that affect the rate of reaction these include - ==> Surface area/size of solid particles ==> Concentration of solutions ==> Temperature ==> Presence of a catalyst Aim In my investigation I am going to look at how concentration affects the rate of reaction, and the reaction I am going to look at is Sodium Thiosulphate (Na2 S2 O3) and Hydrochloric Acid (HCl). The equation for the experiment is shown below - Na2 S2 O3 (aq) + 2HCl (aq) 2NaCl (aq) + S (s) + SO2 (g) + H2O (l) In previous times seeing this experiment I have seen what happens, the solution (which is made up of Sodium Thiosulphate and Hydrochloric acid) has become cloudy, this is because the sulphur is precipitated and sulphur is insoluble. In my experiment I am going to time how quickly it takes the solutions of different concentrations to produce solid sulphur, observing how quickly an "X" is observed under a conical flask of solution. ...read more.

Middle

Method ==> Prepare a table to record the results of your findings ==> Prepare a measuring tube of 10cm3 of hydrochloric acid and pour this into the conical flask ==> Then measure out 50cm3 of sodium thiosulphate and add this to the beaker. ==> Shake the beaker and start to stopwatch. (Remember to start the stop watch at the same point each time the experiment is carried out as this improves accuracy in the experiment.) ==> Then stop the experiment when the "X" underneath the conical flask is obscured by the sodium thiosulphate and hydrochloric acid solution. ==> Record results ==> Again measure out 10cm3 of hydrochloric acid and pour it into the conical flask ==> But this time measure out 45cm3 of sodium thiosulphate and now add 5cm3 of water, add this to the conical flask, shake and then time ==> Stop the stop watch when the solution has obscured the "X" and again record the results ==> Carry this same procedure out for the following measurements - 50cm3 of sodium thiosulphate and 0cm3 of water 45cm3 of sodium thiosulphate and 5cm3 of water 40cm3 of sodium thiosulphate and 10cm3 of water 35cm3 of sodium thiosulphate and 15cm3 of water 30cm3 of sodium thiosulphate and 20cm3 of water 25cm3 ...read more.

Conclusion

A valid method was used so my results agreed with my theory was used so my results agreed with my theory. We repeated and took the average of three recordings of the experiment and, we also measured the volumes of the hydrochloric acid and sodium to eye level. There were a few problems with the experiment, firstly the same flask was used each time, the flask had obtained a coating of sulphur on it from previous experiments and this was hard to was off. This may affect the results of our experiment as there would be more sulphur added to the solution, which would help to make the experiment go cloudy quicker. Another factor that could of potentially affected results is that the experiment was done over two days which means the temperature of the sodium thiosulphate and the hydrochloric acid could have changed, meaning an increase/decrease in temperature would either speed up or slow down the rate of reaction. Measuring the "X" being obscured by the solution by the eye is not the most scientific method: alternatively a colorimeter could be used. Also measuring cylinders aren't the most accurate piece of equipment for measuring volume: a burette could be used as an alternative. ...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

Here's what a teacher thought of this essay

3 star(s)

Generally good data and covers all the main elements needed to secure a high grade. However it is limited by its brief nature. The key elements need to be discussed in more detail with particular care taken to include as much scientific theory as possible. Specific improvements have been suggested throughout.

Marked by teacher Cornelia Bruce 17/04/2013

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. Marked by a teacher

    Marble Chips and Hydrochloric Acid.

    4 star(s)

    Particle Size A larger particle size will have a larger surface area and therefore a larger area for the acid to react on. So, if the experiment contains different sized particles, then the reactions will be happening at varying speeds that will produce inconsistent results.

  2. How does temperature affect the rate of reaction between sodium thiosulphate and hydrochloric acid?

    This is because of the collision theory. Increasing the temperature increases the speed of the reacting particles and faster particles collide more often than slow ones. The increase in the number of collisions leads to an increase in the rate of reaction. Increasing the temperature also gives the particles more energy so that they collide with more violence.

  1. Investigation on how long a candle burns under a glass beaker.

    We will place the candle onto the safety mat and light it. Carefully, one of us will cover the lit candle with the beaker, whilst the other shall start the stopwatch. As soon as the candle goes out the stopwatch shall be stopped, measured and the result will be recorded into the results table.

  2. Investigation on the Effect of Temperature on the Rate of Reaction between Sodium Thiosulphate ...

    There are three ways to increase this in liquids: increase the speed of the particles, increase the concentration of particles, or use a catalyst. To change the concentration, the molar density of the reactants would have to be changed. However, temperature can be used to increase the speed of the particles.

  1. The effects of caffeine on reaction time

    2 0 4 15 325 13 2 0 5 15 340 13 0 2 6 16 289 12 3 0 7 16 353 9 1 5 8 16 404 12 3 0 9 16 420 14 1 0 10 16 295 14 0 1 11 17 502 13 0 2

  2. The reaction between sodium thiosulphate and hydrochloric acid:Looking at the graph the order of ...

    They are not changed chemically, though sometimes they may be changed physically. Catalysts and activation energy To increase the rate of a reaction you need to increase the number of successful collisions. One possible way of doing this is to provide an alternative way for the reaction to happen which has a lower activation energy.

  1. To Compare the Concentration of the Enzyme Catalase in Plant v. Animal v. Fungal ...

    The results were then recorded. The pilot experiment also help to determine the amount of tissue, substrate (H2O2) and buffer, which would be used in the actual investigation. Method Firstly the tissue was cut using a knife or scalpel, and then the tissue was crushed in a pestle and mortar.

  2. The Rates of Reaction Between HCl and Na2S2O3.

    I believe the experiment was quite suitable for this investigation because of how easy it is to repeat each experiment. There are some ways that I could expand this investigation to give me a different set of results. Instead of using concentration as the variable, I could use temperature or movement.

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