Explosive Uncorking
Teachers Copy (4th-7th graders)
Fundamentals
 Acid-base Chemistry
 Formation of hypotheses
 Differentiation of variables and their experimental outcome
 Finding the average and forming a conclusion
Overview
Students will work in groups of two. Each group will be given a 12 oz. bottle and
one cork. They will need to run a total of four different experiments. The different
experiments will test the different variables: water or acetic acid (vinegar) as the solvents
and sodium bicarbonate (baking soda) or Alka-Seltzer as the solid. By testing the
different solvents and different solids, the students will see which combination has the
most profound results. The results will be determined by measuring the distance of the
flight of their cork, then after averaging the class data, a conclusion can be drawn
concerning the most energetic reaction.
Analytic testing in the lab showed that the reaction that produced the most gas
(CO2) was vinegar and sodium bicarbonate. The second most was vinegar and AlkaSeltzer followed by water and Alka-Seltzer. Water and sodium bicarbonate did not
produce any gas.
Given that this reaction is the result of acid-base chemistry, the Alka-Seltzer or
sodium bicarbonate acts as the base. Acetic Acid is a weak acid but a stronger acid than
water. It is this reason why water and sodium bicarbonate do not react; water does not
protonate enough to initiate the neutralization reaction.
The same volume of liquid will be used throughout the experiments as well as the
same mass of either Alka-Seltzer or sodium bicarbonate. This is to eliminate other
variables in the form of more reactants should product more gas. By maintain the same
amount of reactants we can be certain that they resulting distance of the flight is only due
to the different reactants and not their proportions.
For the first test, the groups will crush the Alka-Seltzer tablets with the mortar
and pestle, then measure out 3 grams using a balance. The groups will also measure out
80 mL of water using 100mL graduated cylinders. In the subsequent trials all the
reagents will already have been measured out to expedite the preparation time.
Background
The principle behind this experiment is acid-base chemistry. When the two are
introduced together, a neutralization reaction occurs resulting in the sodium bicarbonate
(baking soda) releasing carbon dioxide in the form of gas. This gas pressure acts as the
propellant to fire the cork. The main ingredient in Alka-Seltzer tablets is sodium
bicarbonate. The vinegar will be a better solvent compared to water as it is more acidic.
When an acid is placed in a solution, hydrogen molecules are ‘donated’. These free
moving hydrogen protons are then ‘accepted’ by the base (the sodium bicarbonate). This
results in bonds breaking in the sodium bicarbonate molecule to form CO2 gas and water
as the products.
Water is unable to cause this effect to the sodium bicarbonate as it is not a strong
enough acid. Water will produce a reaction with Alka-Seltzer tablets as the Alka-Seltzer
tablets have an acid as part of their ingredients. Once the tablet is placed in water, the
acid allows the reaction to take place.
Materials (listed for a class of 20 with groups of 2)
 12 12oz. bottles (two extra)
 1 gallon of vinegar
 3 Alka-Seltzer tablets per group
 16 corks (6 extra)
 One box of baking soda
 Markers to color the groups cork
 Safety goggles for each student
 2 rolls of paper towels
 10 mortar and pestles
 4 balances
 4 100mL graduated Cylinders
 5 yard sticks
Procedure
1. Students will be divided into groups of 2 (or one group of three if there is an
unequal number). Each group will be given one bottle and one cork. First, students
will put on their safety goggles and instructed not to remove them until the end of
class. Then the groups will have a few minutes to decorate their bottle and cork.
During this time, paper towels, balances, and chemicals will be set out.
2. Students will be instructed to take one Alka-Seltzer tablet and crush it into a
powder using the mortar and pestle. Then taking turns using the balances, they will
measure out 3 grams of Alka-Seltzer. This can be done on a piece of paper placed
on top of the balance. As a class, they will be instructed how to use and tare the
balance.
3. Students will then measure out 80mL of water in a graduated cylinder and pour the
water into their bottles. They will then draw a line to mark where 80mL is on their
bottle so the following trials they do not need to measure out the volume.
Returning to their group area, the instructor will demonstrate a safe uncorking
NOTE: POINT CORK AWAY FROM OTHERS
4. Groups will then be allowed to combine the reagents, cork the bottle and launch.
The distance will be recorded. It is important to try and maintain the same launch
angle. If their cork does not fire, just write a 0 for distant, there will be subsequent
trials so every group should be able to launch their cork. If the cork hits something
changing its trajectory, that should be recorded. All observations throughout the
trials should be recorded.
5. Groups will refill their bottle with water to the line they drew, then using the premeasured amount of sodium bicarbonate. The groups will then add, cork and
measure. There should be no uncorking during this trial.
6. Trials will be run in the same manner this time with vinegar using Alka-Seltzer and
sodium bicarbonate in separate trials. Record all results and observations.
7. Now all the individual data will be collected and the average distance for each
combination will be calculated.
8. The rest of the period will be reserved for discussion about acid-base chemistry,
formation of the gas, why the cork came off and any other things they would like to
change, like using a base for the solvent.
Explosive Uncorking
Student Copy
Today we will be doing an experiment on acidbase chemistry. We will be testing different
combinations of solvents (liquid reagents) with different
bases. The goal is to determine which combination was
the most energetic, measured by the flight of your cork.
This combination will be that of the strongest acid and
strongest base.
Question: Which combination do you think will be the most effective and why?
Water and Alka-Seltzer
Water and Sodium Bicarbonate
Vinegar and Alka-Seltzer
Vinegar and Sodium Bicarbonate
Directions
1. Find a partner (someone you have never worked with).
2. Put your goggles on.
3. Get your bottle and cork and decorate your bottle and cork.
4. Using a mortar and pestle, crush one Alka-Seltzer tablet and using a balance
weigh out 3 grams. You will receive instruction on the use of the balance.
5. Then measure out 80mL of water using a graduated cylinder. Pour the water into
your bottle and with a marker draw a line where the water line is.
6. Watch the demonstration of how to prepare your bottle and fire your cork. Then
predict which of the combinations you think will be the most effective.
7. WITHOUT POINTING THE CORK AT ANYONE, fire your cork and record the
distance and all observations.
8. Refill your bottle to the line you marked with water. Then get a pre-weighed
sample of sodium bicarbonate from your teacher.
9. Record if the cork firers.
10. Fill your bottle to the line with vinegar. Then, using pre-weighed Alka-Seltzer,
launch your cork again and record the distance.
11. Fill your bottle to the line with vinegar, add the pre-weighed sodium bicarbonate
and launch your cork. Record how far it goes.
We will now collect all the data from all the groups and take the average and see which
combination was the best.
Trail
Water and AlkaSeltzer
Water and Sodium
Bicarbonate
Vinegar and AlkaSeltzer
Vinegar and Sodium
Bicarbonate
Class Average Flight
Distance Traveled
Observations
Water and Alka-Seltzer _____________________
Water and Sodium Bicarbonate ___________________
Vinegar and Alka-Seltzer ____________________
Vinegar and Sodium Bicarbonate __________________
Worksheet
Instructions: Using the information from your trials and the class discussion, answer the
following questions. Do not worry about spelling.
1. According to the class average, what was the best combination
Vinegar and Alka-Seltzer
Vinegar and Sodium Bicarbonate
Water and Alka-Seltzer
Water and Sodium Bicarbonate
2. The cause of this is reaction is Acid-Base chemistry. Alka-Seltzer and Sodium
Bicarbonate are bases, water and Vinegar (acetic acid) are both acids. The
stronger the acid, the further the flight of the cork. Which is the stronger acid,
Vinegar
or
3. Why did the cork come off for some of the trials?
4. Why did we crush up the Alka-Seltzer tablets?
Water?
5. As this is the result of Acid-Base chemistry, what do you think would happen if a
base was used instead of water of vinegar? That is to say, what would happen
from a base-base reaction? (There is no wrong answer)
6. Is there anything else you would like to test? (Perhaps more sodium bicarbonate
or a something different than water of vinegar) How do you think your change
would affect the experiment?