In addition I am also checking how different variables affect my experiment and also how I can make my test more precise, reliable and accurate.
Tripod Method Firstly I will draw a small dark cross on a piece of paper and place it on a bench mat. I will then put 40cm3 of sodium thiosulphate into a conical flask and place it on a tripod and gauze.
I will heat the solution for a few minutes until the desired heat is reached, i. Next I will place the conical flask on top of the cross, pour 5cm3 of hydrochloric into the hot sodium thiosulphate solution and time how long it takes for the cross to disappear.
On each experiment I will take three readings and work out an average from the data I have obtained. Below are diagrams to illustrate and explain my method Fair Test To ensure that this experiment is fair I will control the variables, i.
I will keep everything constant apart from the variable I am changing-temperature. Therefore, I will make sure that I only change the temperature of the reaction mixture and keep the volume and concentration of the sodium thiosulphate, the volume and concentration of hydrochloric acid and the pressure of all the mixtures the same.
Furthermore I will measure out the volumes of both the sodium thiosulphate and hydrochloric acid to the greatest degree of accuracy I can manage.
I will also try to make my timing and the heating of the sodium thiosulphate solution as accurate as possible. Variables There are different variables which can be changed. I am, however due to my line of enquiry, going to change the temperature of the solution.
The independent variables will be the initial volume and concentration of sodium thiosulphate, and the initial volume and concentration of hydrochloric acid. Below is a table to show the effect of changing different variables.
Safety I will make sure I handle the sodium thiosulphate solution and hydrochloric acid with care. I will also be careful when heating up the solutions and will at all times wear safety goggles and also remain standing throughout the experiment. Furthermore I will be careful not to spill anything and will take extra care when doing the experiment.
Results Below is a table showing my results from the main investigation I can see from observing the table that the first part of my prediction was correct. As the temperature increases the rate of reaction increases too, due to more collisions and more successful collisions, caused by the increase in temperature.
I am going to draw a graph analyse by results properly. It also has a line of best fit to show the consistency and accuracy of the results. There are no anomalous results which shows that the experiment was very accurate.
Furthermore, the graph is a perfect curve It is obvious that there is a general trend in the results. As the temperature increases, the time taken for the sodium thiosulphate solution to become cloudy decreases. This is because as the temperature increases, the reactant particles move more quickly.
In addition to this, more particles have activation energy. This means more of the particles collide and more of the collisions result in a reaction, so the rate of reaction increases. My results do support the first part of my prediction.
Evaluation All of my results were accurate and fitted the pattern of results.
I did not have any problem whilst carrying out my investigation apart and do not believe I could have done it any better without specialist equipment with plenty of time.
The quality of my evidence is good. There were no points on my scatter graph that were not on or close to the line of best fit.
The range of my results were also suitable to make good observations and conclusions By comparing the repeated times on each of the experiments I can see that they were similar and each one was within two seconds of each repeat.
From this evidence I believe my results were very reliable. This might have occurred for several different reasons, such as the fact that the temperature control might not have been exactly the same or that my judgement of when the cross may have disappeared might not have been exactly the same for each one.
In order to provide additional evidence and extend my investigation to find out more and back up my conclusion I could perhaps repeat the experiment using specialist equipment.
I could also change the initial volume of either the hydrochloric acid or sodium thiosulphate solution and see if I get a similar pattern of results. If the results were consistent and accurate I could use them to back up my original theory. To further investigate the decomposition of sodium thiosulphate I could change the concentration of hydrochloric acid and sodium thiosulphate or use a catalyst in the reaction.
Overall I think that my investigation was successful in obtaining reliable results.- Sodium Thiosulphate and Hydrochloric Acid Reaction Investigation Aim To see the effects of concentration on the rate of a reaction between sodium thiosulphate and hydrochloric acid. Background information The collision theory briefly: For a reaction to occur particles have to collide with each other.
In conclusion to this experiment, M of acid was the best to use as it had the best measurable reaction time. Equipment The equipment we will be using during this experiment is: GCSE Chemistry - Sodium Thiosulphate Coursework We must produce a piece of coursework investigating the rates of reaction.
The effect of temperature on rates of reaction Aim: The aim of this experiment is to find out if the reaction rate of sodium thiosulphate solution and hydrochloric acid will be affected by a temperature change.
- Reaction Between Hydrochloric Acid and Sodium Thiosulphate Introduction I will be conducting two experiments to determine how two factors affect the rate of reaction in the reaction between hydrochloric acid and sodium thiosulphate. It .
Enthalpy 2|Page Anjelina Qureshi Mrs Gravell Rates of Reaction Coursework Chemistry Year 11 Enthalpy, in chemistry, is the heat content in a chemical reaction.
The enthalpy change is the amount of heat absorbed or released when a chemical reaction occurs at a constant pressure. Chemistry Plan I am going to produce a piece of coursework investigating the rate of reaction, selecting a variable to see how this affects the rate.
The rate of reaction is the rate of loss of a reactant or the rate of formation of a product. The rate is measured by dividing one by the time the reaction took to take place.