Part I PhET Investigation of Acids & Bases Name:__________________________________________
pH Scale Simulation
Directions:
1. Open the pH Scale Simulation
https://phet.colorado.edu/en/simulation/ph-scale
a. There are 3 Parts to the Simulation
i. Macro
ii. Micro
iii. My Solution
2. Start with the Macro Option
Part A: Pre-Simulation Research Questions
1. Write the following definitions of acids and bases.
a. Arrhenius Definition
Arrhenius acid is any species that increase the hydronium ion H3O+ concentration in a
solution.
Arrhenius base is the species that increase the hydroxide ion OH - concentration in a solution.
b. BrØnsted-Lowry Definition
According to the BrØnsted-Lowry concept, acid is any species that can act as a proton donor
(donate protons), and base is any species that can act as a proton acceptor.
Part B: Macro
1. Open the Google Sheets file in Moodle, Acids Bases Ph.
2. In the first column, list each of the 12 possible substances.
3. In each row, you will be filling in the appropriate values for pH, [H 3O+], [OH-], Product of [H3O+] & [OH-]
4. For now use the pH Meter, measure and record the pHs of all 12 substances. (The other values will be gathered
in Part III.)
Questions
1. What is the pH range for an acid?
pH range for an acid is between 0 and 7.
2. What is the pH ranger for a base?
pH range for a base is between 7 and 14.
3. When is a solution is considered neutral? What pure substance has a pH of 7?
1
, A solution with pH equal to 7 is neutral. Pure water has pH = 7, hence it is neutral.
4. What happens to the pH of the solution when more of the substance is added?
pH of the solution does not change.
5. What happens to the pH of the solution when water is added to the solution?
It becomes higher for acidic solutions, and lowers for basic solutions. In other words, it becomes
closer to the neutral value of 7.
6. What does pH measure?
pH measures the concentration of hydronium ions (H3O+) in the solution.
7. What basic equation is used to calculate the pH of a solution?
pH = -log[H3O+]
Part C: Micro
1. Switch over to the Micro Option of the simulation.
2. Record the concentrations for the H3O+ and OH- ions for each solution in the data table/Google Sheet you
created in Part II.
a. Use the following format : for 1.0 x10 -7 type in 1.0 E-7
3. Calculate the product of the two ions ( [H 3O+], x [OH-] ) and record in the table.
2
pH Scale Simulation
Directions:
1. Open the pH Scale Simulation
https://phet.colorado.edu/en/simulation/ph-scale
a. There are 3 Parts to the Simulation
i. Macro
ii. Micro
iii. My Solution
2. Start with the Macro Option
Part A: Pre-Simulation Research Questions
1. Write the following definitions of acids and bases.
a. Arrhenius Definition
Arrhenius acid is any species that increase the hydronium ion H3O+ concentration in a
solution.
Arrhenius base is the species that increase the hydroxide ion OH - concentration in a solution.
b. BrØnsted-Lowry Definition
According to the BrØnsted-Lowry concept, acid is any species that can act as a proton donor
(donate protons), and base is any species that can act as a proton acceptor.
Part B: Macro
1. Open the Google Sheets file in Moodle, Acids Bases Ph.
2. In the first column, list each of the 12 possible substances.
3. In each row, you will be filling in the appropriate values for pH, [H 3O+], [OH-], Product of [H3O+] & [OH-]
4. For now use the pH Meter, measure and record the pHs of all 12 substances. (The other values will be gathered
in Part III.)
Questions
1. What is the pH range for an acid?
pH range for an acid is between 0 and 7.
2. What is the pH ranger for a base?
pH range for a base is between 7 and 14.
3. When is a solution is considered neutral? What pure substance has a pH of 7?
1
, A solution with pH equal to 7 is neutral. Pure water has pH = 7, hence it is neutral.
4. What happens to the pH of the solution when more of the substance is added?
pH of the solution does not change.
5. What happens to the pH of the solution when water is added to the solution?
It becomes higher for acidic solutions, and lowers for basic solutions. In other words, it becomes
closer to the neutral value of 7.
6. What does pH measure?
pH measures the concentration of hydronium ions (H3O+) in the solution.
7. What basic equation is used to calculate the pH of a solution?
pH = -log[H3O+]
Part C: Micro
1. Switch over to the Micro Option of the simulation.
2. Record the concentrations for the H3O+ and OH- ions for each solution in the data table/Google Sheet you
created in Part II.
a. Use the following format : for 1.0 x10 -7 type in 1.0 E-7
3. Calculate the product of the two ions ( [H 3O+], x [OH-] ) and record in the table.
2
