• Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month
  1. 1
  2. 2
  3. 3
  4. 4
  5. 5
  6. 6
  7. 7
  8. 8
  9. 9
  10. 10
  11. 11

Reaction between sodium thiosulphate solution (Na2S2O3) and dilute hydrochloric acid (HCl)

Extracts from this document...


The reaction between sodium thiosulphate solution (Na2S2O3) and dilute hydrochloric acid (HCl) can be used to investigate the affect of concentration upon reaction rate. The equation for this reaction is: Na2S2O3 + 2HCl 2NaCl + H20 + SO2 + S The concentration of Na2S2O3 is 0.16 mol/cm3 and the HCl is 2 mol/cm3. You must use 50cm3 of sodium thiosulphate solution each time and 5cm3 of hydrochloric acid. The reaction is carried out in a flask placed on a piece of white paper, which has a cross upon it. During the reaction a yellow precipitate of sulphur is formed. 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. You can measure the time from the start of the reaction until the cross can no longer be seen. This is the rate of reaction i.e. the rate of sulphur formation. I am going to use the investigation between dilute hydrochloric acid and sodium thiosulphate to investigate the affect of concentration upon reaction rate. The rate of a reaction tells us how quickly a chemical reaction has taken place. ...read more.


There is a second reason why the rate increases. Some colliding particles don't bang together hard enough to start a reaction i.e. they don't have enough energy. At higher temperature the particles are moving faster consequently they crash together harder and there are more successful collisions. Catalysts also increase the rate of reaction. The energy needed to start a reaction is called the activation energy. A catalyst lowers the activation energy so that a collision needs less energy in order to be successful. Hence more collisions become successful and so the reaction goes faster. I predict that as the concentration of sodium thiosulphate increases the rate of reaction will increase. Increasing the concentration of a solution means that there will be more particles per dm3. The more particles that there are the more will collide per second and so the rate of the reaction increases. The collision theory states that for a reaction to occur particles have to collide with each other. Not only do particles need to collide but they also need to collide with enough energy otherwise they just bounce off each other harmlessly. ...read more.


Place a conical flask on top of this X 3) Measure 50cm3 of Sodium Thiosulphate using 1 of the measuring cylinders 4) Add to the conical flask 5) Using another measuring cylinder measure 15cm3 of Hydrochloric acid 6) Add to the conical flask, swirl the contents and start the stopwatch immediately 7) Stop the stopwatch when the mixture has turned sufficiently cloudy so that the letter X can no longer be seen 8) Record the time in your results table 9) Repeat the experiment for all of the six concentrations, using the last measuring cylinder to measure out the water 10) Then repeat the whole procedure so that there are two sets of results for each concentration and take the average 11) However if one of the sets of results is entirely different to the other, perform a third experiment to replace the anomalous result. A pair of goggles will be worn during the experiment in order to protect the eyes. And as an extra safety measure bags will be put away and stools pushed below benches. I will record my results in a table, like the one below. Volume of H2O Volume of Na2S2O3 Time (S) Concentration of Na2S2O3 Rate - 1/time (cm2) (cm2) 1 2 Average (moles/dm3) (1/secs or S-1) ...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. Marked by a teacher

    In my investigation I am going to look at how concentration affects the rate ...

    3 star(s)

    But high concentration will mean a higher rate of reaction, as there are more particles in the same volume of solution. More collisions will occur between the reacting particles which lead to more successful collisions in a given period of time, which increases the rate of reaction.

  2. Investigating the effect of temperature on the reaction between Sodium Thiosulphate (Na2S2O3) and Hydrochloric ...

    The Main Experiment Method I will heat the water and the sodium thiosulphate over a Bunsen to the desired temperature. I will add the acid, and start the stop watch. An X will be placed beneath the conical flask containing the solution, and when this is no longer visible the stop watch will be stopped, and the time recorded.

  1. The Rates of Reaction Between HCl and Na2S2O3.

    Temperature affects how the molecules move, and as the temperature rises, the time for the reaction to take place should decrease. Movement would be an interesting experiment, as it would be hard to control the movement, so it could probably never be fair.

  2. Free essay

    Close Your Eyes

    I was bored and wanted Louise back, to hold her. After a bit longer I decided to go looking for her. I walked through the tress surrounding the park until I heard her voice. I walked into a clearing and saw that she had her back to me.

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

    The more they vibrate the more chance there is that they will collide with another particle, thus causing the rate of reaction to increase. In a chemical reaction, the reactants collide with each other. Pressure High pressure Low pressure Not many collisions Marble in dilute hydrochloric acid 1 Large marble

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

    Graph 1- a graph that reflects my prediction, that the rate of reaction will decreases with time and as the concentration decreases and shows the relationship between the two 1.0 0.5 concentration of reactant 0.25 0 2 4 6 8 10 12 14 16 time in seconds I expect there

  1. An investigation of factors which might affect the rate of the reaction between sodium ...

    stopwatch and time the reaction until the 'X' is obscured from view. When I can no longer see the 'X' then I will stop the clock and record my results. I feel this is a fairly accurate way of recording my results although it does rely on the accuracy of

  2. Find out how the rate of hydrolysis of an organic halogen compound depends on ...

    Notice that in Example 2, the order of the reaction with respect to I- is one, even though there are two I- ions in the balanced equation for the reaction.

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