Properties of Acids Bases

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Slide 1

ACIDS AND BASES

Slide 2

CA Standards

Slide 3

Properties of Acids

Acids are proton (hydrogen ion, H+) donors

Acids have a pH lower than 7

Acids taste sour

Acids effect indicators

Blue litmus turns red

Methyl orange turns red

Acids react with active metals, producing H2

Acids react with carbonates

Acids neutralize bases

Slide 4

Acids are Proton (H+ ion) Donors

Strong acids are assumed to be 100% ionized in solution (good H+ donors).

Weak acids are usually less than 5% ionized in solution (poor H+ donors).

HCl

H2SO4

HNO3

H3PO4

HC2H3O2

Organic acids

Slide 5

Acids Have a pH less than 7

Slide 6

Acids Taste Sour

Citric acid in citrus fruit

Malic acid in sour apples

Lactic acid in sour milk and sore muscles

Butyric acid in rancid butter

Organic acids are weak acids. Some are used as flavoring agents in food.

Slide 7

Organic Acids

Organic acids all contain the “carboxyl” group, sometimes several of them.

The carboxyl group is a poor proton donor, so ALL organic acids are weak acids.

Slide 8

Acids Effect Indicators

Blue litmus paper turns red in contact with an acid.

Methyl orange turns red with addition of an acid

Slide 9

Acids React with Active Metals

Acids react with active metals to form salts and hydrogen gas.

Mg + 2HCl  MgCl2 + H2(g)

Zn + 2HCl  ZnCl2 + H2(g)

Mg + H2SO4  MgSO4 + H2(g)

Slide 10

Acids React with Carbonates

2HC2H3O2 + Na2CO3

2 NaC2H3O2 + H2O + CO2

Slide 11

Effects of Acid Rain on Marble (calcium carbonate)

George Washington:

BEFORE

George Washington:

AFTER

Slide 12

Acids Neutralize Bases

HCl + NaOH  NaCl + H2O

Neutralization reactions ALWAYS produce a salt and water.