Name: _______________________
REACTION RATES LAB
Go to my website http://misskaleyhanson.wikispaces.com
Click on Science 9
Unit 2
Reaction Rates Lab
You will be investigating how TEMPERATURE, PARTICLE SIZE, and
CONCENTRATION affect rates of reaction.
At the top of the page there are three tabs for each of the above. Do each of the tabs.
First click on the TEMPERATURE tab. Then, to access the interactive, click on the
graphic on the page to launch it. Use the interactive by following the instructions
below and answer the questions for each part.
TEMPERATURE
You will investigate how changes in temperature affect the reaction rate of an
antacid tablet dissolved in water.
Problem: How does temperature affect the rate of reaction?
Make a HYPOTHESIS for the problem:
Follow the Procedure below:
1. Read the safety poster.
2. Click on the equipment cupboard.
3. Select the equipment that you will use for this experiment (take out the
beaker, hot plate, thermometer, antacid, timer.)
***note the reset button in the right hand corner is used to return settings
back to normal *****
4. Place the ice in the beaker of water and record the temperature in the data
table below.
5. Place the antacid tablet in the beaker, start the timer by clicking on it.
Stop the timer once the antacid is dissolved. Record how long this took in
your data table.
6. Reset the lab equipment and set the hot plate to 1. Drop in the antacid
and record the time it takes to dissolve in the data table.
7. Repeat this process for hot plate settings of 2, 4, 6, 8, and 10.
Name: _______________________
Observations
Data Table
x axis
y axis
Temp
Time (s)
(°C)
Conclusion
1. Which factor is the independent variable (what you change)?
2. Which factor is the dependent variable (what changes as a result of
changing the manipulated variable)?
3. What variables are the control variables (do not change)?
4. Initially, what happened to the time it took the antacid tablet to dissolve as
you increased the temperature?
5. Between which two temperatures was there the fastest reaction rate?
6. Write a general statement that would answer the question stated in the
problem.
7. At what temperature did the time it takes for the antacid to dissolve begin
to increase?
Analysis and Extension
1. Make a graph of your results. Give the graph a title and label both axes.
Name: _______________________
2. Why do you think your graph is not linear (a straight line)? In other words,
why does the time it takes the antacid to dissolve not continue to decrease
as the temperature increases.
PARTICLE SIZE
You will investigate the change in reaction rate when varying sizes of zinc
particles are reacted with sulfuric acid.
Problem: How does particle size affect the rate of reaction?
Write you HYPOTHESIS for the Problem above:
Follow the Procedure below:
1.
2.
3.
4.
5.
Read the safety poster describing the safe handling of acids.
Place the 8.0 mm Zn sample in the beaker of H2S04 acid.
Record the time it takes for the sample to dissolve, in the data table.
Click the Reset button and choose Reset Lab Equipment.
Repeat these steps for each successively smaller sample, recording the
dissolving time for each in the data table.
6. Return your equipment to the cupboard when you are finished
Observations:
Data Table
x axis
y axis
Avg. size of
particles of
Zn (mm)
Time (s)
8.0
4.0
2.5
1.5
0.5
Name: _______________________
Conclusion:
1. What evidence is there that a chemical reaction is taking place?
2. Which variable is the independent variable?
3. Which variables are control variables?
4. How does the size of the particle affect the rate of reaction?
Extension:
1. Create a graph of your results. Give the graph a title and label both axes.
CONCENTRATION
You will investigate the reaction rates of varying concentrations of sulfuric acid
combined with magnesium metal.
Problem: How does concentration affect the rate of reaction?
Write a HYPOTHESIS for the Problem above:
Procedure
1. Read the safety poster describing the safe handling of acids.
2. Open the lab supply cupboard and place your materials on the lab bench.
3. Set your H2SO4 Concentration level to 5%.
4. Use the forceps to place the magnesium ribbon in the beaker.
5. Use the timer to determine the time it takes for the magnesium ribbon to
completely dissolve.
6. Record the concentration and time in the data table.
Name: _______________________
7. Use the Reset button to reset the lab equipment.
8. Repeat these procedures for concentrations of 10%, 20%, 30%, 40%, and
50%. Record the information in the data table.
Observations:
x axis
CONC
H2SO4
%
5
10
20
30
40
50
y axis
Time (s)
Conclusion:
1. What evidence is there that a chemical reaction is taking place?
2. Which variable is the independent variable?
3. Which variables are control variables?
4. How does the concentration of the acid affect the rate of reaction?
Extension:
1. Suggest a reason why the time it takes for the magnesium ribbon to
dissolve does not continue to decrease.
2. Create a graph of your results.
Label the axis and give it a title.