Carbon Dioxide from Antacids Lab Report
Purpose: To measure the amount of carbon dioxide gas produced when antacid tablets
dissolve in water. To compare the number of gas molecules to the volume in a flexible
Materials: 6 antacids tablets (Alka Seltzer works best!) Mortar and Pestle
3 round rubber balloons Funnel
10ml Graduated Cylinder Tape Measure
1. Label the balloons #1, #2, and #3.
2. Crush one antacid tablet using the mortar and pestle and pour the pieces into
balloon #1 using the funnel.
3. Crush two antacid tablets using the mortar and pestle and pour the pieces into
balloon #2 using the funnel.
4. Crush three antacid tablets using the mortar and pestle and pour the pieces into
balloon #3 using the funnel.
5. Using the funnel, add 5ml of water to balloon #1, immediately pinching off the
balloon below the funnel to trap the gas being produced. Carefully, tie off the
balloon and quickly measure the circumference of the balloon at its largest point.
6. Continue measuring the circumference of the balloon #1 every five minute for
twenty minutes while periodically shaking the contents of the balloon.
7. While timing and measuring balloon #1, repeat Step 5 and 6 for balloon #2.
8. While timing and measuring balloons #1 and #2, repeat Step 5 and 6 for balloon
#3. Staggering your measurements in this way will allow you to work with all
balloons simultaneously as opposed to consecutively (i.e. saving time).
Balloon 1 Balloon 2 Balloon 3
Initial Circumference (cm)
After 5 minutes
After 10 minutes
After 15 minutes
After 20 minutes
Use the maximum circumference of each balloon to calculate the volume of each balloon.
Assume that the balloons are spherical. Show your work and then add your values to
your table below.
Maximum Radius of Balloon Volume of CO2
Circumference (cm) c=2πr (cm) v = 4πr3/3 (cm3)
1. Make a line graph of balloon volume verses number of tablets. According to your
graph, describe the relationship between the number of tablets used and the
volume of carbon dioxide gas produced.
2. Assume that the balloon is filled with carbon dioxide gas at 20˚C and standard
pressure. Calculate the mass and number of moles of carbon dioxide gas in each
balloon at maximum inflation.
3. If a typical antacid tablet contains 2.0g of sodium hydrogen carbonate, show how
your carbon dioxide results compare with the theoretical values by calculating
your percent yield.
4. How does this lab relate to the concepts being discussed in class? What concept is
this lab reinforcing? Be detailed and clear in your response.