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

Investigate the effect of concentration on the rate of a reaction using the reaction between Sodium Thiosulphate and Hydrochloric acid as an example.

Extracts from this document...


Rates of Reaction Donna Murray 10m2 Aim: To investigate the effect of concentration on the rate of a reaction using the reaction between Sodium Thiosulphate and Hydrochloric acid as an example. Background: A reaction will only occur where the particles of the reactants meet and combine. This is called the collision theory. That means that it stands to reason that to increase the rate of reaction it is necessary to cause more particles to collide harder and make it happen more often. Molecules must collide before they react. Before colliding molecules react, they must have energy equal to or greater than the activation energy for the reaction. It is possible, using the collision theory, to calculate the number of collisions occurring or second. The energy needed to start a chemical reaction is called activation energy. The rate of reaction is how fast the reaction is. An example of a reaction that is slow is that of the rusting of iron. A fast reaction is that of hydrogen and oxygen. When they react, they form water vapour. To investigate the effect of concentration on the rate of a reaction using the reaction between Sodium Thiosulphate and Hydrochloric Acid as an example. Changing the conditions could affect the rate of a reaction. There are lots of factors that affect the rate of a chemical reaction. ...read more.


* When both reactants are added together in a conical flask, place a beaker over the top. This prevents any gasses escaping that are produced. Diagram: Prediction: The rate of reaction is the rate of loss of a reactant or the rate of formation of a product during a chemical reaction. It is measured by dividing 1 by the time taken for the reaction to take place. There are five factors which affect the rate of a reaction, according to the collision theory of reacting particles: temperature, concentration (of solution), pressure (in gases), surface are (of solid reactants), and catalysts. I have chosen to investigate the effect concentration has on a reaction. I predict that the more dilute the Sodium Thiosulphate Solution becomes, the longer it will take to react and for the solution to become cloudy so the cross is no longer visible. And I predict that the results will show a pattern and the time taken will increase as the solution becomes more dilute. I think this because if you refer back to the collision theory you will see it says that before colliding molecules react, they must have an energy equal to or greater than the activation energy for the reaction. This means that the graph of results drawn up will have a positive correlation and will probably be curved as the increase in rate of reaction will not be exactly the same as the concentration is increased. ...read more.


I think I do have enough evidence to draw up a conclusion as I have done, because I recorded 3 sets of results along with an average result and a table for the rate of reaction, which uses the collision theory to calculate the number of collisions per second. I think the experiment worked well and the results backed up my prediction - the fact that the more dilute the solution, the longer it took to react. I think that to improve this experiment I should have used a light and sensor with a computer in place of the piece of paper with a cross on it. I would do this by placing a light under the flask, which would probably be held on a tripod, and a censor above the conical flask, which would be connected to the computer. This would recognize the light through the censor, and when the solution became cloudy, the light would be blocked, therefore causing the censor to detect this, and the computer will record the time taken. This would be extremely accurate. Another thing that I could use to improve this experiment is to use a burette to get a more accurate reading of the solutions, which could have varied the results. It would make measuring the solutions a lot more accurate and therefore the results may have varied. All in all I think this was a good experiment and the best that could have been done with the time and resources available. The results supported my predictions and they seem to be fairly reliable results. ...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 ...

    For example when the concentration is 0.15 Mol.dm-� the time for the reaction is 20.00 seconds, at 0.12 Mol.dm-� the time is 28.16 seconds and at 0.09 Mol.dm-� the time taken is 38.28 seconds. This is because as the sodium thiosulphate is diluted further then it becomes less concentrated.

  2. The aim of this coursework is to investigate the rate of reaction between sodium ...

    Work out any averages and more importantly the rate of reaction. Variables The independent variable is going to be the concentration of sodium thiosulphate, as this is what we are going to change. The dependent variable is the time it takes for the solution to go opaque (rate of reaction), as this is what we are going to be measuring.

  1. Rates of Reaction- Hydrolysis of Urea by Urease

    Temperatures of 70 �C and 75 �C were chosen to trial theory B, and when conducted, the results from the experiment showed that theory B was feasible. At 70�C the average reaction time was 41.27s, a 50.23% decrease from the average reaction time at 26�C.

  2. An Experiment to Investigate the Effect of Changing the Concentration of Hydrochloric Acid on ...

    To prevent any change in room temperature all windows will be closed, air conditioning will be switched off and no bunsen burners will be used in the laboratory during the experiment. To keep the temperature constant I will use a thermometer and check the room temperature every so often.

  1. What factors effect the rate of reaction at which Alka-Seltzer tablets react with water.

    However at higher temperatures the pattern will break down giving unreliable results and the trend in the graph will show this. Therefore the Alka - Seltzer tablet dropped into the hottest water may give unreliable results. I think this because the water I am using is tap water, which I know contains temporary hardness.

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

    Fair Test In order to keep the experiment a fair test and get accurate and reliable results I need to: * Use a dry beaker for every experiment. If it is wet it could affect the concentration of the hydrochloric acid, although only a little bit.

  1. ICT modelling spreadsheet - This coursework was designed to investigate the uses of electricity ...

    In the day rate spreadsheet, the column calculating individual costs would be needed to be filled in using absolute cell references (see introduction for explanation). The absolute cell reference equation, to fill the items' costs, for the night rate is '=$k$7 x G (row number'.

  2. Investigate various ways of increasing the rate of a chemical reaction and evaluate which ...

    temperature T1 (in K) Relative probability of kinetic energy occurring Kinetic Energy The above can be expressed mathematically: n=noe-E/RT where n is the number of molecules with energies greater the E, the activation energy, no is the total number of molecules, R is the gas constant, equal to 8.3145 J K-1 mol-1 and T is the absolute temperature.

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