The pH Scale1
What does pH stand for, and what does it measure?
Potential of Hydrogen, measuring acidity of basicity.
What is the specific pH level that this project is on?
pH 13
This highly corrosive chemical, used in soap making and drain cleaners usually has a pH of 13-14.
Lye
What are two typical products formed when an acid and a base react in a neutralization reaction?
A salt and water.
Name one common household material that can be used as a pH indicator to show color changes.
Universal indicator solution or red cabbage juice.
What are the pH ranges for acidic, neutral, and basic solutions respectively?
Solutions with a pH less than 7, exactly 7, or greater than 7.
A strong base or highly alkaline.
Explain why household bleach, containing sodium hypochlorite has a pH around 12-13
Sodium hypochlorite is a strong base that produces hydroxide ions when dissolved in water.
What type of substance would you add to neutralize a strong base with a pH of 13?
How does a universal pH indicator work to help us determine a liquids pH?
What are the two key ions whose concentrations determine if a solution is acidic?
Hydrogen ions and hydroxide ions
What does a pH of 13 indicate about the relative concentrations of OH- and H+ ions?
Why are many liquid drain cleaners formulated with strong bases to achieve a high pH?
They require a highly alkaline environment to react with organic matter through saponification.
Describe the basic chemical interaction between ions that occurs during neutralization.
H+ ions from the acid react with the OH- from the base to form water.
Describe the setup for a stomach antacid demonstration the shows neutralization.
Dilute vinegar with a pH indicator, then adding a crushed antacid tablet.
How does a water’s dissociation explain why pure water is considered neutral.
Water can dissociate into both H+ and OH- ions, and in pure water, their concentrations are equal
Name one common household product that can typically have a pH of 13.
Lye, Bleach, or Liquid Drain Cleaner.
Name one environmental area where understanding pH is critically important.
Acid rain, soil pH, ocean pH.
Why is the amount and concentration of the neutralizing agent important when neutralizing a solution?
To ensure the solution reaches the desired pH without becoming too acidic or basic.
From a chemistry perspective, explain why baking powder makes cake rise.
Baking powder contains acid base components that reach when wet to produce CO2 gas, making it rise.
What does it mean when we say the pH scale has a logarithmic nature?
Each whole pH unit represents a tenfold change in the concentration of hydrogen ions
Why does a strong base like Lye result in a pH near 13-14?
It completely dissociates in water, releasing a large number of OH- ions.
Besides cleaning products or the environment, name another daily life area where pH significantly affects processes.
The human body or food and cooking.
It would only partially neutralize the base, leaving the solution with a high pH.
If you had a large spill of pH 13 strong bases and add only a small amount of weak acid, what would be the result?
Name at least three key requirements for a successful pH interactivity, according to the rubric.
It must be interactive for the audience, safe, use readily available materials and clearly explain the connection to pH at a chemical level.