ACID-BASE THEORIES

Svante Arrhenius Johannes Brönsted Thomas Lowry

Aim and ObjectivesAim: How do you categorize a chemical?

Objectives:

1.Students should be able to identify acids based on the Arrhenius and Alternate theories.

2.Students should be able to use the Reference Tables to identify acids and bases.

3.Students should know the properties of acids and bases.

Arrhenius Acid

• H+ ion is the only positive ion in an aqueous solution.

The H+ ion is also called a __________. Why?

Ex. HCl(l) H+(aq) + Cl-(aq)

The H+ ion reacts with water to produce the__________________.

Ex. H+(aq) + H2O(l) H3O+(aq)

Note: Not all substances that contain H are acids. Ex. CH4

Arrhenius Base

• OH- ion is the only negative ion in an aqueous solution.

NaOH Na+ + OH- [Typical Bases]

NH3 + H2O NH4+ + OH- [Ammonia]

CH3NH2 + H2O CH3NH3+ + OH- [Amines]

Alternate Acid/Base Theory• Acids are proton donors. [AD]• Bases are proton acceptors.• Take into consideration the forward and

reverse reactions.

HCl + H2O ↔ H3O+ + Cl-

FWD Reaction: Acid = HCl because it gives up an H+,

Base = H2O because it accepts the H+.

REV Reaction: Acid = ________, Base = _________

Acid Base Review Table

Characteristic Acid BaseTaste

Electrolyte?

Litmus

Phenolphthalein

React with Metals to Produce H2?

Arrhenius Theory

Alternate Theory

Regents Questions

HW: OB: Topic 9: Acids and Bases Q 1-3, 5, 24-27, 32, 36

Aim: How do we categorize a chemical?

Acids and bases are categorized by…