Temperature, surface area, concentration, and a use of catalyst are the four different ways in which you can increase the rate of reaction.
Temperature:
When you raise the temperature of a system the particles bounce around a lot more (because they have more energy). When they bounce around they are more likely to collide. That means more collisions will be successful. When you lower the temperature the particles are slower and collide less. That temperature drop lowers the rate of reaction.
Concentration
In a reaction where one or both reactants are in low concentrations the particles are spread out and will collide with each other less often resulting in fewer successful collisions.
In a reaction where one or both reactants are in high concentrations the particles are crowded close together and will collide with each other more often, resulting in an increased number of successful collisions.
Catalyst
A catalyst is a substance, which speeds up the rate of a chemical reaction (catalyst doesn’t run out). Different reactions need different catalyst. Catalyst work by reducing the activation energy.
Surface area
Large particles have a small surface area in relation to their volume this means that less particles are exposed and available for collisions. This means less collisions and a slower reaction
Small particles have a large surface area in relation to their volume, this means that more particles are exposed and available with collisions. This means more collisions and a faster reaction.
Preliminary Experiment
Preliminary Table
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My preliminary results tell me that the higher the concentration of HCL, the faster the rate of reaction.
Prediction
I predict that the higher the concentration of HCL the faster the rate of reaction. I predict this because in a reaction where one or both reactants are in high concentrations the particles are crowded close together and will collide with each other more often, resulting in an increased number of successful collisions.
Diagrams
Apparatus
Conical flask
Hydrochloric Acid
Sodium Thiosulphate
Goggles
Measuring Cylinder
Stopwatch
Thermometer
Beaker
‘X’ (drown onto a piece of paper)
Method
- Get all the apparatus as listed above (making sure you put on your goggles).
- Next set up the five conical flasks so they are in a row on a table.
- Pour out 10ml of sodium thiosulphate into the other measuring cylinder. Pour this into the conical flask with the HCL in it and as you pour the thiosulphate into the conical flask start to time how long it takes for the ‘X’ to disappear.
- Do this experiment again but for each of the other concentrations
- Then put all the information into a table and graph.
