THE pH SCALE

​•The pH scale is a measurement system used to indicate the concentration of H+ ions in a solution.

•Solutions with a pH below 7 (0 to 6.99) are called acidic or (acids), because they have more H+ ions than OH- ions. (The lower the pH the greater the acidity).

•The pH scale ranges from 0-14.

pH Scale, Acids & Bases

​•The stronger the acid is, the lower its pH.  Ex: battery acid is more acidic than lemon juice.

•The stronger the base is, the higher its pH.  Ex: bleach is more basic than baking soda.

THE pH SCALE

•At a pH of 7, the concentration of H+ ions and OH- ions is equal. Thus making 7 on the pH scale neutral. *Pure water has a pH of 7.

•Solutions with a pH above 7 (8 to 14 on the pH scale) are called basic or (bases), because they have more OH- ions than H+ ions.

•The higher the pH, the more basic the solution.

ACIDS

•An acid is any compound that forms H+ ions in a solution.

•Acidic solutions contain higher concentrations of H+ ions than pure water and have a pH value below 7.

•Examples of acids are; stomach acid, lemon juice, vinegar, hydrochloric acid and tomato juice

ACID

​•The strongest acids have pH 0

•The weakest acids have pH 6.

•Acids will taste sour.

•Acidic foods are a common cause of heart burn.

Examples: lemon juice, tomatoes, grapes, blueberries

BASE

​•A base is a compound that produces hydroxide ions (OH- ions) in solution.

•Basic, or alkaline, solutions contain lower concentrations of H+ ions than pure water and have pH values above 7.

BASE

​•The strongest bases have pH 14.

•The weakest bases have pH 8.

•Bases will taste bitter.

•Most household cleaners are basic solutions.

•Examples of bases are; (all cleaning agents) bleach, shampoo, oven cleaner, and ammonia