Chemical Reactions 5 - Acids and Bases

Alkaline

relating to or containing an alkali (base); having a pH greater than 7

pH scale

A range of 0-14 to show the concentration of hydrogen ions in a solution Tells how strong or weak acids or bases are <7 acid, 7 neutral, >7 basic (alkaline)

Neutralization

A reaction of an acid with a base, yielding a solution that is not as acidic or basic as the starting solutions were

Base

A substance that tastes bitter, feels slippery, and turns red litmus paper blue They have pH levels above 7.

Acid

A substance that tastes sour, reacts with metals and carbonates, turns blue litmus red. They have pH levels lower than 7.

Acids Used in Industry

Muriatic (HCl) - cleans concrete and bricks Sulfuric - car batteries, acid rain Nitric - plant fertilizers Phosporic - plant fertilizers, Coke and Pepsi

Common Bases

Soap Shampoo Detergent Tonic water Ammonia Sodium hydroxide

Blue litmus paper

Stays blue in the presence of bases but turns red with acids

Red litmus paper

Stays red in the presence of acid but turns blue with bases

Four Properties of Bases

Bitter taste Slippery feel pH >7 turn red litmus paper blue

Indicators

Compounds that change color in the presence of an acid or a base Examples: pH paper, litmus paper, phenolphthalein solution, cabbage juice, tea

Hydrogen

Gas produced when acids react with metals

Neutral

Substances that are neither acidic nor basic Example: water

Four Properties of Acids

Taste sour pH < 7 React with metal to produce hydrogen gas React with carbonates Turn blue litmus paper red

Litmus test

a coloring material that turns red in acid solutions and blue in alkaline solutions

Acidic

a pH below 7; contains more H+ ions than hydroxide ions (OH-)

Salts

a product (ionic compound) made from the neutralization of an acid with a base

Basic

pH above 7 (alkaline); more OH- ions than H+ ions