Acids and Bases. Describe 4 properties of acids Describe 4 properties of bases Identify four uses of acids and bases.

Describe 4 properties of acidsDescribe 4 properties of bases Identify four uses of acids and bases

AcidBase Indicator

Every liquid is either an acid or a base except distilled water which in neutral

The pH scale indicates the number of Hydrogen ions to the power of 10

A solution with an excess of H+ ions

Def: any compound that increases the number of hydronium ion H30+

A solution with an excess of OH- ions when dissolved in water.

Taste sourReacts with metals such as

magnesium, zinc and iron to produce hydrogen gas H2

Turns blue Litmus paper redCause skin to burnReact with bases to form water and

chemical salt

1. Taste bitter2. Feel slippery or soapy3. Strong bases will burn skin4. Turns red Litmus paper blue

“opposite of acids”5. React with acids to form chemical

salt and water

Acid Lemon juice Orange juice Vitamin C (acetic

acid) Coca-cola Car battery

(sulfuric) Stomach acid (HCl) Carbonic acid PAGE 370

Base Milk of Magnesia Maalox Drain cleaner

(Ca2OH) Oven cleaner

(NaOH) Cleaning products

(ammonia) PAGE 373

What are some common day examples of acids that you use in your life? Bases?

When you taste a “warhead” candy, what do you taste?

Do you think electricity will like to flow through acids and bases? Why do you think this…think about the definitions…

Questions from page 373 # 2-8

pH and Neutralization

pH is an indicator that measures the amount of H+

0-6.9 is acidic7 is pure water

(neutral)7.1 and greater is

basic

The concentration of hydrogen is the key

the more hydrogen ions the lower the pH (acid) or the more acidic the solution is

The less hydrogen the higher the pH (base) or the more basic the solution is

Indicators (litmus paper) tell us if solutions are acidic or basic

Aqueous▪ A solution that is

mostly water Strong Acid

▪ pH of 0-4

Weak Acid▪ pH of 4-7

Neutral▪ pH of 7

Strong Base▪ pH of 10-14

Weak Base▪ pH of 7-10

The strength of an acid depends on its pH (number of Hydrogen ions ). A dilute solution of HCl will burn a hole in your clothes. SO THE MORE H+ that break off, the more ACIDIC THE MORE OH- that break off, the more basic

The less of H+ or OH- that breaks off, the weaker the acid/base

Neutralization

Acids in water solution separate into hydrogen ions (H+)

HCl + water H+ + Cl-Bases in water solution separate

into hydroxide ions (OH-)

NaOH + water NH4 + OH-

Neutralization A reaction between an acid and a base

is called neutralization After mixing an acid solution with a

base solution the pH of the new solution will change. Sometimes result in a neutral solution▪ Factors include, concentration, volume, and

identities

Products Salt (an ionic compound) made from the

neutralization reaction between an acid and a base

HNO3 + KOH H2O + K+ + NO3-

Some salts are soluble and remain in solution

Some salts are insoluble and precipitate In scientific terms, what are salts?

Sodium chlorideNaCl

Potassium iodideKI

Calcium chlorideCaCl2

Potassium chlorideKCl

Calcium carbonateCaCO3

Ammonium nitrateNH4NO3

Food flavoring, preservation

Additive that prevents iodine deficiency

De-icer for roads

Salt substitute in foods

Found in limestone and sea shells

Fertilizer, active ingredient in cold packs

Human Digestion HCl in stomach breaks down food (pH 2) HCO3- (bicarbonate) in small intestine

raises pH to 8 by bonding with the H+ ions enzymes of digestion work the best at pH 8

Other Human Facts Skins pH protects against being over run

by bacteria Tears are slightly acidic