Reaction Rates
Purpose:
To investigate the effect of concentration, surface area, temperature and the nature of the
reactants on the rate of a chemical reaction.
Science 10
Materials:
marble chips (calcium carbonate chips same size and shape)
Powered calcium carbonate
beakers
HCl solutions (hydrochloric acid) (different concentrations)
Thermometer
Ethanoic acid
Magnesium ribbon
graduated cylinder
Introduction Part A.
Do temperature changes affect the rate of reaction? In this experiment you will investigate the role of
temperature in a chemical reaction. This can be done by using different temperatures and recording the
relative rates for the compound to react at these different temperatures.
Procedure: 1. In beaker, #1 add 25.0 mL of 1M HCl at room temperature (20-25ºC). Place the
thermometer in the beaker; stir until the temperature is constant and record temperature.
Add one of the marble chips and record the relative rate of reaction. Compare this
reaction rate to the rate of the reaction below in number 2. (The rate of reaction is seen by
the rate of bubbling.)
2. In beaker #2 add 25 mL of 1M HCl from the hot water bath (at a temperature of 5055ºC). Record temperature of the water bath, and add one of the marble chips to this
warm acid. Again, record the relative rate of reaction.
Questions:
1. What evidence is there that this is a chemical reaction?
2. What happens to the reaction rate as the temperature increases?
3. Why do you think this happens?
Conclusion: Should answer your purpose
Introduction Part B
Do changes in surface area affect the rate of reaction? In this experiment you will investigate the role of
surface area in a chemical reaction. This can be done by using different surface areas of one of the
reactants and measuring the time required for the the reactant compound to disappear.
Purpose: To investigate the effect of surface area on the reaction rate.
Procedure: 1. Add 25.0 mL of 1M HCl to beaker#1 and beaker#2.
2. Obtain a calcium carbonate chip and equal volume of powered calcium carbonate.
3. Add the chip to beaker#1 and the power to beaker#2. Compare the rates of reaction.
Questions:
1. Which sample had the greatest exposed surface area? Why?
2. What happened to the reaction rate as the surface area increased?
3. Why do you think this happened?
Conclusion: Should answer purpose.
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Reaction Rates
Science 10
Introduction Part C
In order to investigate the effect of changing the concentration of one of the reactants on the reaction
time you will prepare dilutions of the hydrochloric acid solution.
Purpose: To investigate the effect of concentration on the reaction rate.
Procedure: 1. Obtain three solutions of hydrochloric acid as follows.
Beaker #1 50 mL of 0.5 M HCL acid
Beaker #2 50 mL of 1.0 M HCL acid.
Beaker #3 50 mL of 2.0 M HCL acid
2. Obtain three pieces of magnesium ribbon, each one centimetre long.
3. Add a piece of magnesium to each beaker and compare the rates of reaction for each
solution.
Questions:
1. Write a balanced chemical equation for this reaction.
2. How does the reaction rate change as the concentration increases?
3. Explain why you think this happens.
Conclusion: Should answer purpose.
Introduction Part D
Does the reactant used change the rate of reaction? In this experiment you will investigate the role of the
reactan in a chemical reaction. This can be done by using different reactantss and recording the relative
rates for each of the different reactants. We will use different acids and react them with the same
compound, calcium carbonate.
Procedure: 1. Add 25.0 mL of 2M HCl to beaker#1 and 25.0 mL of 2M CH3COOH to beaker
beaker#2.
2. Obtain two calcium carbonate chips equal in size and shape.
3. At the same time add the chip to beaker#1 and to beaker#2. Compare the rates of
reaction.
Questions:
1. Write a balanced chemical equation for these reactions.
2. How does the reactant affect the reaction rate?
3. Explain why you think this happens.
Conclusion: Should answer purpose.
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