Brainpop~Acids and Bases

Acid:

A substance that releases H+ ions in an aqueous solution

“aqueous” means: water

Characteristics of Acids:

Acids have a sour taste Acids react with metals

Acids contain Hydrogen

Many are poisonous and corrosive to skin

H

Strong Acids(break down completely to give off many H+ ions)

Weak Acids(only partially breaks down, gives less H+)

Mark Bishop Acid animation

Common Acids:

All others considered Weak (examples)

Strong Acids The Formula

Sulphuric acidHydrochloric acidHybrobromic acidHydroiodic acidNitric acidPerchloric acid

H2SO4

HClHBrHIHNO3

HClO4

Acetic acid (vinegar) HC2H3O2

Carbonic acid HCO3

Weak Acid The Formula

Base:

A substance that releases OH- ions in an aqueous solution

Characteristics of Bases:

Bases usually taste bitter Bases feel slippery Bases contain hydroxide ions STRONG bases are also poisonous and corrosive to skin

OH-

Strong Bases The Formulae

Lithium hydroxideSodium hydroxidePotassium hydroxideRubidium hydroxideCaesium hydroxideBarium hydroxideCalcium hydroxideStrontium hydroxide

LiOHNaOHKOHRbOHCsOHBa(OH)2

Ca(OH)2

Sr(OH)2

Common Bases:

(Hydroxides of Group 1 and Group 2 Metals are STRONG)

All others are WEAK

Some bases (VERY FEW) don’t have OH-

Most commonly: ammonia NH3

Reactions between acids and bases

When and acid and a base react with each other, the characteristic properties of both are destroyed. This is called neutralization.

Reactions between acids and bases

General formula for acid base reaction:

Acid + Base → H2O +Salt

“Salt” means any ionic compound formed from an acid/base reaction

NOT JUST NaCl !!

Neutralization Reaction Animation

Neutralization

HCl + NaOH → H2O + NaCl acid base water salt

NeutralizationAnother Example

HNO3 + KOH → H2O + KNO3

H OHKNO3

acid base water salt

IndicatorsAn indicator is a compound that will change color in the presence of an acid or base

Universal indicator (pH paper) Used for the full pH range

Red Litmus-Turns blue in baseBlue Litmus-Turns red in acid

Phenolphthalein-Turns pink in base

pHpH stands for “potential hydrogen” and is a measure of how many H+ ions there are in solution.

The MORE H+ there are, the LOWER the pH will be.

pH ScaleShows the range of H+

concentrations

High H+ concentration Low H+ concentration