3.9: Describe Experiments to Investigate the Effects of Changes in Surface Area of a Solid, Concentration of a Solution, Temperature and the Use of a Catalyst on the Rate of a Reaction

EFFECT OF SURFACE AREA OF A SOLID ON THE RATE OF REACTION:

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EFFECT OF SURFACE AREA ON THE RATE OF REACTION

Diagram showing the Process of Downwards Displacement to Investigate the Effect of Surface Area on the Rate of Reaction

METHOD: Add dilute Hydrochloric acid into a conical flask Use capillary tube to connect flask to a measuring cylinder placed upside down in a bucket of water (downwards displacement) Add Calcium Carbonate chips into conical flask and close the bung Measure the volume of gas produced in measuring cylinder in a fixed period of time Repeat with different sizes of Calcium Carbonate chips (solid, crushed and powder)

RESULT: As the surface area of solid increases, the rate of reaction will increase (positive correlation) This is because as the surface area to volume ratio of a solid increases, more surface area particles are exposed to the other reactant This allows more frequent successful collisions to occur, increasing the rate of reaction

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EFFECT OF CONCENTRATION OF A SOLUTION ON THE RATE OF REACTION:

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EFFECT OF CONCENTRATION ON THE RATE OF REACTION

Diagram Showing the Apparatus Needed to Investigating the Effect of Concentration on the Rate of Reaction

METHOD: Measure 50 cm3 of Sodium Thiosulfate Solution in a Flask Measure 5 cm3 of Dilute Hydrochloric Acid into a Measuring Cylinder Draw a Cross on a Piece of Paper and Put it Underneath the Flask Add the Acid into the Flask and Immediately Start the Stopwatch Look Down at the Cross from Above and Stop the Stopwatch when the Cross can No Longer be Seen Repeat Using Different Concentrations of Sodium Thiosulfate Solution (Mix Different Volumes of Sodium Thiosulfate Solution with Water to Dilute it)

RESULT: Increase in the Concentration of a Solution, the Rate of Reaction will Increase This is because there will be More Reactant Particles in a Given Volume, Allowing More Frequent and Successful Collisions, Increasing the Rate of Reaction

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EFFECT OF TEMPERATURE ON THE RATE OF REACTION:

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EFFECT OF TEMPERATURE ON THE RATE OF REACTION

Diagram Showing the Apparatus Needed to Investigate the Effect of Temperature on the Rate of Reaction

METHOD: Dilute Hydrochloric Acid is Heated to Set Temperature Using a Water Bath Add the Dilute Hydrochloric Acid into a Conical Flask Add a Strip of Magnesium and Start the Stopwatch Stop the Time when the Magnesium Fully Dissolves Repeat at Different Temperatures and Compare Results

RESULT: Increase in the Temperature, the Rate of Reaction will Increase This is because the Particles will have More Kinetic Energy than the Required Activation Energy, therefore More Frequent and Successful Collisions will Occur, Increasing the Rate of Reaction

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EFFECT OF A CATALYST ON THE RATE OF REACTION:

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EFFECT OF CATALYST ON THE RATE OF REACTION

Diagram Showing the Apparatus Needed to Investigate the Effect of a Catalyst on the Rate of Reaction

METHOD: Add Hydrogen Peroxide into a  Conical Flask Use a Capillary Tube to Connect this Flask to a Measuring Cylinder Upside Down in a Bucket of Water (Downwards Displacement) Add the Catalyst Manganese (IV) Oxide into the Conical Flask and Close the Bung Measure the Volume of Gas Produced in a Fixed Time using the Measuring Cylinder Repeat Experiment Without the Catalyst of Manganese (IV) Oxide and Compare Results

RESULT: Using a Catalyst will Increase the Rate of Reaction The Catalyst will Provide an Alternative Pathway Requiring Lower Activation Energy so More Colliding Particles will have the Necessary Activation Energy to React This will Allow More Frequent and Successful Collisions, Increasing the Rate of Reaction