Acids and BasesAcids and BasesAcids and BasesAcids and Bases

Properties of Acids

Produce H+ (hydrogen) ions in water

Taste sour

Corrode metals

React with bases to form a salt and water

pH is less than 7

Turns blue litmus paper to red “Blue to Red A-CID”

Why the symbol for soda?Why the symbol for soda?

Acetic acid Acetic acid (vinegar)(vinegar)

Ascorbic acid Ascorbic acid (lemon juice)(lemon juice)

Hydrochloric acid Hydrochloric acid (stomach acid)(stomach acid)

Examples of Common Acids

Properties of Bases

Produce OH- ions in water (hydroxyl ions)

Taste bitter, chalky

Are electrolytes

Feel soapy, slippery

pH greater than 7

Turns red litmus paper to blue “Basic Blue”

Properties of Bases

•Many household products contain bases

•Strong bases can be dangerous

Properties of Bases

•Bases can help to ease the effects of too much stomach acid

•They are conveniently called ANTACIDS

Examples of Common Bases

Bleach Laundry detergent Shampoo Soaps, toothpaste Tums, Alka-Seltzer

(antacids)

Water - an acid or base?

Water is neither acidic or basic – it is the only substance that is naturally neutral.

pH = 7 (neutral)

Litmus Paper

• A base will turn litmus blue

• An acid will turn litmus red

Acid-Base Reactions

A reaction between an acid and a base is called a neutralization

The pH scale is a way of expressing the strength of acids and bases.

pH 1-6 = acidpH 7 = neutralpH 8-14 = base

pH Scale

• A pH lower than 7 is acidic

• A pH higher than 7 is basic (alkaline)

• If the pH is 7, the solution is neutral

pH indicators

Indicators are dyes that can be added that will change color in the presence of an acid or base.