ntroduction:
Remember: C=carbon, H=hydrogen, O=oxygen
When CO2 dissolves in seawater, the carbon and oxygen molecules bind together to form carbonic acid,
which is shown in thte following reaction: CO2 + H2O <----> H2CO3
This carbonic acid breaks apart in the water, releasing hydrogen ions and bicarbonate, shown here:
H2CO3 <-----> H+ + HCO3
Hypothesis:
If I blow carbon dioxide CO2 to any kind of water, then it will change the pH (acidity).
Materials Checklist
Pre- lab questions:
1. What gas are you blowing into the water?
2. What happens to the gas when you blow it into the water?
3. How are you measuring change in the water during this lab?
4. What does measuring the pH of the water tell us?
5. After studying the reactions above, how do you think carbonic acid will affect the pH of salt
water?
Lab Procedure Preparation:
1. Assign a role to each group member
2. Familiarize yourself with the Universal Indicator Color Chart
Remember: C=carbon, H=hydrogen, O=oxygen
When CO2 dissolves in seawater, the carbon and oxygen molecules bind together to form carbonic acid,
which is shown in thte following reaction: CO2 + H2O <----> H2CO3
This carbonic acid breaks apart in the water, releasing hydrogen ions and bicarbonate, shown here:
H2CO3 <-----> H+ + HCO3
Hypothesis:
If I blow carbon dioxide CO2 to any kind of water, then it will change the pH (acidity).
Materials Checklist
- 100 mL Saltwater
- Thermometers
- 500 mL beakers
- Hot Plate
- straws
- Ice Bath
- timer
- Tap water
- Disposable Pipet
- 100mL Saltwater with indicator solution
- 0.6mL tube with 0.2mL of (to compare before/after)
- universal indicator solution
- Safety Goggles (1/student) and/or Parafilm
Pre- lab questions:
1. What gas are you blowing into the water?
2. What happens to the gas when you blow it into the water?
3. How are you measuring change in the water during this lab?
4. What does measuring the pH of the water tell us?
5. After studying the reactions above, how do you think carbonic acid will affect the pH of salt
water?
Lab Procedure Preparation:
1. Assign a role to each group member
2. Familiarize yourself with the Universal Indicator Color Chart