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

To find out how the rate of reaction between sodium thiosulphate and hydrochloric acid is affected by changing the concentration.

Extracts from this document...

Introduction

Chemistry investigation - concentration Aim: To find out how the rate of reaction between sodium thiosulphate and hydrochloric acid is affected by changing the concentration. Prediction: The equation between sodium thiosulphate and hydrochloric acid is: Sodium thiosulphate + hydrochloric acid � sulphur + sodium chloride + sulphur dioxide + water Na2S2o3 (aq) + HCl (aq) � S (s) + NaCl (aq) + SO2 (g) + H2O (aq) We draw a black cross on the back of the test tube. When the cross is completely obscured, the reaction will have finished. The black cross will have disappeared because the build up of Sulphur gas particles will form bonds with the liquid particles, creating a solution. The time taken for this to happen is the measure of the rate of reaction. We must do this several times, and change the concentration of sodium thiosulphate. The rate of reaction is a measure of the change, which happens during a reaction in a single unit of time The factors affecting the rate of reaction are: Temperature: All reactions go faster at a higher temperature. In fact, the rate of reaction doubles by a temperature increase of just 10�C. In this experiment, the particles in the thiosulphate and hydrochloric acid will speed up if the temperature gets slightly warmer. Surface Area: The surface area of a solid means the amount of surface that is exposed to the outside. If you cut up a solid into pieces, the surface area gets larger. There are no solids in this experiment, but if we were to add a potato for example, the higher its surface area, the more exposed it will be to the acids and the quicker the reaction will take place. ...read more.

Middle

If these points are not taken into account, results will be come very inconsistent and I would have to deem the results inaccurate. Safety Precautions: There are a lot of safety issues I must abide by in this experiment also. * I must remember that the substances that we use in this experiment can be very harmful if used the wrong way. * When I do this experiment, it may be necessary to wear safety goggles, as things are very unpredictable, and even though it is very unlikely that the solution would come out of the test tube during the experiment, one must still be cautious of spills. * I must make sure that coats and bags are all out of the way while doing the experiment. Ties and hair should be tucked out of the way, so they do not make contact with any of the chemicals. * We should also try our best not to spill any chemicals, as these substances can stain clothing and other upholstery * I must not eat or drink in the lab while dealing with these harmful chemicals, if I handle chemicals without washing my hand afterwards, and then handle food, I could inadvertently swallow some of the acid on my hand, and I might fall ill. * Plasters should cover any open wounds that I may have, as any chemical spillage on the wound can cause me immense pain and possible infection of it. * If any chemical is spilt onto any part of the body, most notably the hands, I must make sure that I clean them afterwards thoroughly as any contact with acid-covered hands to my eyes or my mouth will cause great and extensive injury. ...read more.

Conclusion

I would have also prepared five different test tubes to use, instead of frantically cleaning one each time after use. In the science lab I was using, the sodium thiosulphate and the hydrochloric acid were constantly being spilt, and in some cases, were in contact with each other, this meant that the pair reacted before entering the solution. I would have set them very far apart i.e. one at each end of the classroom. Finally, I would have asked for a white scientist's coat, or something like that to wear, because fibres from my clothes might have contaminated the solution. Though unlikely, and didn't affect my experiment, it could ruin someone else's experiment. Next time, I would also make sure that the artificial light maintains the same intensity, as the higher the intensity, the hotter the air around it become. Since temperature affects the rate of reaction, it could affect my experiment. I will also make sure that my eyes are the same distance from the test tube and the black cross, because the closer you are to the black cross, the better you can see it. For each experiment, if I keep changing the distance between the black cross, and myself the times aren't going to be consistent. I will stay at a constant distance so that my observations of the black cross are constant. For further work, I could have made the solution more concentrated. For instance I could have the very concentrated solution, where there is no water in the solution. In the other extreme, I could make the solution totally diluted, but I think that could have tested my patience. I think that I could have diluted the mixture next, by adding more water each time than hydrochloric acid. This will test anyone's prediction and could lead to some interesting 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 Aqueous 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 Aqueous Chemistry essays

  1. Investigating the effects of changing the concentration of different solutions on the refractive index ...

    as a denser medium slows down the speed of light when the light ray enters it. Diagram 2 Diagram 3 However, when light passes from a denser to a less dense transparent material, e.g. from glass or water to air, it is bent away from the normal, which means that

  2. Rates of Reaction

    the concentration of the hydrochloric acid, so for example, acid at 2M could be diluted slightly which could affect the accuracy of the results. In order to keep this variable controlled we must make sure that the conical flask is cleaned thoroughly after usage.

  1. In order to find out the exact concentration of sulphuric acid, I will have ...

    Also it is very important to check that before each titration is conducted, the burette is placed at eye-level and sulphuric acid does not exceed the graduation mark. The bottom of the meniscus should always touch the line for accurate results.

  2. My Aim is to see how concentration of acid will affect the time it ...

    .In my pilot I used higher quantities of acid but I discovered that doing this is a waste of time and wasteful because you can make the concentration differ however much acid and water you choose to vary. I used high amount of acids but then discovered the overall solution had the same concentration so I have been less wasteful.

  1. Investigate the rate of reaction between colourless solutions, hydrochloric acid and Sodium Thiosulphate by ...

    two molar To make this experiment a fair test: o I must measure out all reactants accurately, especially the hydrochloric acid and water if I wish to change the concentration of acid. o I must also make sure that the amount of sodium thiosulphate is equal to the hydrochloric acid (even if diluted)

  2. What factors affect the rate pf reaction between sodium thiosulphate and hydrochloric acid?

    of reactants in the solution therefore in creasing the chance of collisions - Size of particles; if a solid has a bigger surface area then this increases the chance of collision between particles. - Catalyst; A catalyst increases the number of successful collisions by giving the particles a surface to stick to therefore maximising the number of successful collisions.

  1. What effects the rate of a reaction

    The actual reason for the hydrogen to be produced is because Magnesium has two electrons in its outer shell. Hydrogen has just one electron overall and Chorine has seven electrons in its outer shell. When the reaction between the magnesium and the chorine and hydrogen which is together (Hydrochloric Acid)

  2. Investigate the effect that concentration has on a reaction on these factors: Temperature rise, ...

    the right amounts of hydrochloric acid in one of them and sodium hydroxide in the other. After measuring them, I will first put 20cm3 of the alkali into a plastic cup and then move the cup under the burette containing the 40cm3 of acid.

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