Ch 14.1 Properties of Acids and Bases

Acids Are sour to taste React with bases to produce salts and

water. React with metals and release H2 gas Turn litmus paper red Conduct an electric current. Examples: citrus fruit, tomatoes, HCl, and

stomach acid

Acid Nomenclature Binary Acid: an acid that contains only

2 different elements: Hydrogen &one of the more electronegative elements.

Naming: begins with hydro- followed by the root of the 2nd element & ends in -ic.

Oxyacid: an acid that is a compound of hydrogen, oxygen, and third element, usually a nonmetal.

Common Industrial Acids

Sulfuric Acid Nitric Acid Phosphoric Acid Hydrochloric Acid Acetic Acid

Bases Are bitter to taste Feel slippery React to neutralize acids, forming salt and

water Turn litmus paper blue Conduct an electric current. Examples: Baking Soda, Soaps, Ammonia,

and NaOH

Arrhenius Acid

Produces H+ in an aqueous solution. Once present, the H+ combines with water to form H3O+ (called hydronium).

The dissociation of HCl looked like:HCl H+ + Cl-

But it was actually:HCl + H2O Cl- + H3O+

Arrhenius Base

Produces OH- in solution. Examples:

NaOH Na+ + OH-

NH3 + H2O NH4+ + OH-

Dissociation

The strength of an acid or base depends on the amount of dissociation that occurs. This depends on the polarity of the bond and the ease at which the bond can break.

Organic Acids containing carboxyl/acid groups COOH, like vinegar, are generally weak.

Ch 14.2 Acid-Base Theories

Bronsted-Lowry Acids & Bases

Do not require aqueous solutions. Acids are defined as proton (H+) donors

and bases are proton (H+) acceptors. Examples:

HCl + NH3 NH4+ + Cl-

A BH2O + NH3 NH4

+ + OH-

A B

Monoprotic and Polyprotic Acids

Monoprotic: An acid that can donate only one proton (H+) per molecule.

HCl + H2O H3O+ + Cl-

Polyprotic: An acid that can donate more than one proton (H+) per molecule. Diprotic: Can donate 2 protons. H2SO4

Triprotic: Can donate 3 protons. H3PO4

Lewis Acids and Bases

Lewis of electron dot structure fame Where both Arrhenius and Bronsted-

Lowry acids contain or produce H+, Lewis acids don’t have to.

An acid is defined as an atom, ion, or molecule that accepts an electron pair to form a covalent compound.

A base donates an electron pair.

Lewis Acids and Bases

They can exist in solid, liquid, or gas phase.

ExamplesH+ + NH3 NH4

+

H2O + HCl Cl- + H3O+

BF3 + F- BF4-

Ch 14.3Acid-Base Reactions

Conjugate Acids and Bases When a Bronsted-Lowry acid gives up

a proton, it becomes a B-L Base because it can then accept a proton. Reactions usually involve two acid-base pairs.

HCl + NH3 NH4+ + Cl-

A B CA CBH2O + NH3 NH4

+ + OH-

A B CA CB

In general, strong acids have weak conjugate bases and weak acids have strong conjugate bases.

Proton-transfer reactions favor the production of the weaker acid and weaker base.

Amphoteric Substances Substances which can be an acid or a

base. Whether it acts as one or the other

depends on the strength of what it reacts with.

Example: H2O:

H2O + NH3 NH4+ + OH-

H2SO4 + H2O H3O++ HSO4-

Neutralization Reactions

A base neutralizes an acid forming salt and water. But things are not quite so simple. The return of the SPECTATOR ION!

HCl + NaOH NaCl + H2O Base Dissociation

NaOH Na+ + OH-

Acid DissociationHCl +H2O Cl- + H3O+

Then write Overall and then Net Ionic.

Acid Rain

Rain that is very acidic Industrial processes produce gases

such as NO, NO2, CO2, SO2, and SO3. These can dissolve in water producing acidic solutions that fall to the ground in the form of rain. This Acid Rain can erode statues and affect ecosystems.