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

SodiumThiosuplhate

Extracts from this document...

Introduction

Tom Gregan How does changing the concentration of sodium thiosulphate affect the rate of reaction with hydrochloric acid? For my case study I was set the task of how the concentration of sodium thiosulphate affects the rate of reaction with hydrochloric acid. Here is the chemical equation for the reaction, Hydrochloric acid + sodium thiosulphate sodium chloride + water + Sulphur dioxide + Sulphur 2HCL + Na2S2O3 2NaCl + H2O + SO2 + S Hydrochloric acid and sodium thiosulphate are clear liquids but when mixed the solution should go cloudy; when it does we know a chemical reaction has taken place. Carrying out this case study will hopefully help us find out if the rate of reaction is related to the increase in concentration of the reaction. About Collision Theory Collision Theory basically explains how chemical reactions occur and why reaction rates differ for different reactions. This theory is based on the idea that reactant particles must collide for a reaction to occur, but only a certain fraction of the total collisions have the energy to connect effectively and cause the reactants to transform into products. This is because only a portion of the molecules have enough energy and the right orientation at the moment of impact to break any existing bonds and form new ones. ...read more.

Middle

We can't control the dependent variable which for example would be the conditions e.g. temperatures of the room we carried out the experiment in this could effect the independent variable in many ways for example it could speed up the rate of reaction or even slow the rate of reaction down we don't know and unfortunately we couldn't control it. The controlled variable in this experiment was the amount of water and sodium thio solution used each time. Sodium Thiosulphate used (cm�) Water Used (cm�) Acid Used (cm�) Experiment 1 Time cross disappeared (s) Experiment 2 Time cross disappeared (s) Experiment 3 Time cross took to disappear) (s) Average Time Cross Disappeared (s) Rate of Reaction 1000/s (s-1) 10 40 5 270.12 277.64 271.14 217.14 3.68 20 30 5 104.04 102.10 103.07 103.07 9.70 30 20 5 69.16 75.35 69.53 69.53 14.38 40 10 5 55.83 56.45 56.14 56.14 17.81 50 0 5 35.01 37.21 36.11 36.11 27.69 Anomalous Results Table of results for main investigation What my reactions did The changing concentration of sodium thiosulphate affects the rate of reaction with the hydrochloric acid; Chemical Equation 2HCL + Na2S2O3 the reaction would reach its end point quicker if it was like this 2HCL + 3Na2S2O3 . ...read more.

Conclusion

I think that there could have been a number of errors made here therefore repeating the experiment for this molarity would be the best idea. My results are first order kinetics because as the molarity of the solution increases, so does the reaction time. My graph also shows that there is a positive correlation and that the results are proportional because as x increases, y also increases. First order reactions mean that as the rate of reaction doubles, so does the concentration. At 0.05M the rate of reaction was 2 S-1, at 0.1M the rate of reaction was 3.6 S-1. This means that as the concentration doubles the rate of reaction almost doubles as well. However, I think that with more experiments and with the improvements I suggested earlier, I think that the rate of reaction would double when the concentration of the solution does. I can also prove this by working out the gradient: m= y/x. The gradient of my graph was 1.3. There is a large increase in the rate of reaction between 10 ml of sodium thiosulphate and 20 ml of it. However, there was only a small increase in the rate of reaction between 30 and 40 ml of sodium thiosulphate. The results could be improved if more experiments were carried out because we could eliminate more anomalous results that occurred which would give very 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 Organic Chemistry 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 Organic Chemistry essays

  1. Marked by a teacher

    Investigating the rate of reaction between magnesium and hydrochloric acid

    3 star(s)

    Preliminary work 2 This method is similar to preliminary work 1 however I have decided to experiment in different temperatures to see whether it makes a difference to my results. Basically I have collected hydrogen in different temperatures of water in the beaker surrounding the magnesium and hydrochloric acid reaction.

  2. Titration experiment - write up

    I also used a white tile and made sure I was at the correct eye level, so that I wasn't looking at the meniscus from a wrong angle. Getting this wrong would have caused me to begin my experiment again. Hence, I made sure I was extremely precise and cautious.

  1. hydrogen peroxide experiment

    Both of these steps require less energy than the energy required without the catalysts presence. Without the catalysts presence the reactants have to collide with sufficient energy for the H-O bond to break, allowing the two H2O molecules to form, and also to form the O-O bond, allowing the O2 molecule to form.

  2. In this report the effects of fire and explosion are examined based on quantitative ...

    The burning velocity is increased if the proportion of oxygen in the atmosphere is increased. This is of extreme significance as there is many occasions where oxygen enriched atmospheres are produced accidentally, such as leakage from an oxygen supply system in a hospital.

  1. To investigate how concentration affects the rate of reaction between magnesium ribbon and dilute ...

    Fair Test: - * I will use the volume of dilute hydrochloric acid (20cm3) and the length of the magnesium (2.5cm) as the controls for this experiment. * The magnesium will have to be cleaned, because it will have reacted with the oxygen in the air causing the outer layer to be oxidised and become magnesium oxide.

  2. GCSE Chemistry Revision Notes - everything!

    All electrolytes contain ions. Electricity passes in and out of the electrolytes via electrodes. In a metal or graphite, electricity is simply a flow of electrons. The movement of the electrons doesn?t produce any chemical change in the metal or graphite. Graphite and metal contain free-moving (delocalised)

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