Acids and Bases Bundle 4: Water

What is an Acid? An acid is any species that increases the concentration of H+ ions in a solution.

pH is a measure of how much H+ ions are present 0 – 6 pH is Acidic 7 = neutral solution

Acid Excess H+ pH below 7 Low pH = Strong Acid

What is a Base? A base is any species that increases the concentration of OH- ions in a solution.

pOH is a measure of how much OH- ions are present 8 – 14 pH is Basic pOH values are opposite of pH values

Base Excess OH- pH above 7 High pH = Strong Base

pH and pOH =14

Calculating Acid Relationship For each ONE UNIT step you go down in pH, the solution is 10 times more acidic. For each ONE UNIT step you go up in pH, the solution is 10 times less acidic.

Calculating Base Relationship For each ONE UNIT step you go down in pOH, the solution is 10 times more basic. For each ONE UNIT step you go up in pOH, the solution is 10 times less basic.

Examples How many times more acidic is a solution with pH of 3 than a solution with the pH of 6? 10 x 10 x 10 = 1000 times more acidic How many times less acidic is a solution with pH of 5 than a solution with the pH of 3? 10 x 10 = 100 times less acidic

Examples How many times more basic is a solution with pH of 10 than a solution with the pH of 8? 10 x 10 = 100 times more basic How many times less basic is a solution with pH of 9 than a solution with the pH of 13? 10 x 10 x 10 x 10 = 10,000 times less basic

What have you learned? Is this solution more Acidic or more Basic or Neutral? How do you know?

What have you learned? Is this solution more Acidic or more Basic or Neutral? How do you know?

What have you learned? Is this solution more Acidic or more Basic or Neutral? How do you know?

Solution A (pH 4); Solution B (pH 2) Which one has more H+ ions? Which one has less OH– ions? Solution A (pH 11); Solution B (pH 13) Which one has more OH- ions? Which one has less H+ ions?