• 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
  12. 12
  13. 13

An investigation into the effect of concentration on the rate of chemicl reaction between sodium thiosulphate and hydrochloric acid.

Extracts from this document...


Aim The aim of this investigation is to find out and observe how concentration affects the rate of reaction. I am going to investigate the changes caused to the solution of hydrochloric acid and sodium thiosulphate when the concentration is changed. Background information The rate or speed of a chemical reaction is a measure of how fast the reaction takes place. The rate of reaction gives the measure of how the reaction is proceeding. How is the rate of reaction found? To find the rate of reaction, it is necessary to measure either: * The amount of a reactant used per unit of time (or) * The amount of product produced per unit of time. If one products of the reaction is a gas, it can be collected and its volume measured as it is evolved by means of a gas syringe. The rate of evolution of gas can then be used as a measure of the reaction. Example- during the experiment between Magnesium and dilute hydrochloric acid, the products are magnesium chloride and hydrogen. The gas can be collected and its volume measured at intervals using the apparatus below. Collision theory of reaction Reaction takes when particles collide. Most collision does not produce a reaction because colliding particles need a minimum energy to react when they collide. E.g.: 2H2 (g) + O2 (g) ==> 2H2O When H2 and O2 molecule collide, they must have energy to break the H-H and the O=O bonds in H2 and O2 before they can react to form water. The collisions must be enough of energy to overcome the energy barrier; called the activation energy. The more frequently particles collide, the faster is the reaction. How rate of reaction is measured 1) Measure how long it takes for a reaction to be completed. ...read more.


Safety The things that I will need to do to keep my experiment safe for myself and other students around me are as follows: * I will wear goggles to protect my eyes * I will wear a lab coat to protect my clothes and skin * I will tuck my stool out of the way, so no one can trip over it. * I will stand up whilst doing my experiment, so that just in case if something spills, I will be able to get away fast * I will not leave the apparatus at the side of the table, so it cannot get knocked over. Plan The reaction between sodium thiosulphate and hydrochloric acid is well known and has been used to study the rates of reaction. When these chemical are combined they form a sulphur precipitate in the form of a suspension which turns the transparent opaque. Hydrochloric + Sodium thiosulphate sodium + water + sulphur + sulphur acid chloride dioxide HCl (aq) + Na2S2O3 (aq) NaCl (aq) + SO2 (g) + S (s) + H2O (l) A simple set of experiments may be performed to determine the effect of concentration on the rate of reaction. By using a conical flask with a cross marked piece of paper positioned underneath it, then add 25cm3 of sodium thiosulphate and then add 25 cm3 of 0.3 mole of hydrochloric acid then start the stop watch and time the duration of the cross to disappear. The pattern will disappear after a specific quantity of sulphur has formed The faster the reaction, the shorter the length of time during which the cross is invisible. The experiment is carried out several times with solution of hydrochloric acid to different concentrations. ...read more.


If I could do this experiment again, this should hopefully give me an extra set of results that prove my results are reliable and my prediction is right. This all depends if I have more time to do so. I believe that the experiment was designed well but there were a few problems. Although the initial rate of reaction ( which is what I am concerned with in this investigation) seemed to fit a trend, the rate of reaction curves of all concentration on the graphs crossed only 0.6 M concentration acid didn't crossed. The reason is that these anomalities could occurred, is that I could not measured the acid or sodium thiosulphate out correctly from the measuring cylinder. Also, I could have started the stop watch slightly after or before I actually should. In the second graph the only concentration that I could make straight line is 1.0 M concentration of hydrochloric acid. However, it is a strong positive correlation which mean that as I increase the concentration the rate of reaction increases. The result on the first graph which is a curve graph there was only one problem which on 0.6 M, it is not going with the curve line. And on the second graph there is two point which are o.7 M and 1.0 M. I conducted all experiment for each concentration at the same time to save time. An error in my graphs (plotting, drawing curves) could have also affected the calculated rates of reaction. The information that I collected could be adequate to support my conclusion fully. However, I could collect more evidence by doing more repeats and maybe doing more different concentration of hydrochloric acid. Additional work, which could be carried out, is to repeat the experiment using, a wider range of concentrations. ?? ?? ?? ?? Mona Ibrahim Chemistry Coursework 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

    Chemistry Coursework - How the concentration effects the rate of reaction between sodium thiosulphate ...

    It is quite obvious form the tables of results above that as the rate of reaction increased, so did the time for the reaction occur. This shows some kind of link and shows that the sets of results maybe in proportion to one another because as the rate of reaction

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

    However, the graph agrees with the prediction to the extent of temperature affecting the rate of reaction directly, and that the increase in the rate of reaction increases with the temperature. This can be coupled with the similarity of the real line to the theoretical line, which I believe is evidence enough that this increase is exponential.

  1. The reaction between Sodium Thiosulphate and Hydrochloric Acid.

    Apart from that one change, everything else in my procedure is exactly the same. Results: Unfortunately, the computer doesn't tell you how long it takes before the light is no longer visible; all it does is plot a graph of the decreasing light intensity.

  2. Experiment to Investigate the Rate of Reaction between Hydrochloric Acid and Sodium Thiosulphate, with ...

    is converted into kinetic energy, making the particles move around faster, resulting in more useful collisions (since they collide more often). If the temperature decreases then the opposite will happen and the rate of reaction will slow down. The hydrochloric acid and the sodium thiosulphate must be changed for each

  1. Investigating the effect of temperature on the rate of reaction between Sodium Thiosulphate and ...

    This is based on the collision theory. Therefore my prediction was correct, as it was exactly the same as the conclusion. This shows that I managed to use my scientific knowledge to make an accurate prediction. Explanation: When gases or liquids are heated the particles gain kinetic energy and move faster.

  2. How does changing the concentration of the Hydrochloric acid affect it reactions with Magnesium?

    jam and so not giving correct results or that the bung was not placed on the top of the side arm tube fast enough which allowed gas to escape. I conducted all three experiments for each temperature at the same time to save time.

  1. An investigation into the effect of concentration on the rate of reaction. The disappearing ...

    I will also be able to use the results from my preliminary test in order to use as a benchmark for when I undertake my real test in order to check that I am doing it right. For my preliminary test I will only do a few tests, as any more is not necessary.

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

    When the concentration of sodium thiosulphate was 0.150M, the average time it took the cross to disappear was 27 seconds. At 0.125M, the average time for the cross to disappear was 33 seconds. At 0.100M, the average time was 42 seconds, whilst at 0.750M; the average time was 58 seconds.

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