Study Guide for General Chemistry

General Chemistry 2 Study Guide*

Exam 3, Spring 2014

Chapter 16 (Acid-Base Equilibria)

Know the definitions of Arrhenius, Bronsted-Lowry and Lewis acids and bases.
- Arrhenius: Acid dissolved in water increases conc. Of H+ ions. Base dissolved in water increases conc. Of OH- ions

- Bronsted-Lowry: Acid: substance that donates a proton to another substance Base: substance that accepts a proton from another substance

-Lewis: Acid: electron pair acceptor Base: electron pair donor

Be able to identify Arrhenius, Bronsted-Lowry and Lewis acids and bases in an acid-base reaction equation.

Understand the concept of conjugate acid-base pairs and how each member differs from the other by one proton.
-conjugate base formed by removing a proton from the acid

-conjugate acid formed by adding a proton to the base

Be able to write and identify conjugate acid-base pairs.

Understand that acid-base reactions are proton transfers involving two sets of conjugate acid-base pairs.
- The stronger an acid, the weaker its conjugate base, and the stronger a base, the weaker its conjugate acid.
-Strong acid completely dissociates in water: the conjugate base of a strong acid shows negligible basicity.
-Weak acid partially dissociates in water, mixture of acid and conjugate base: the conjugate base of a weak acid is a weak base.
- negligible acidity has some hydrogen but does not behave like acid in water: conjugate base is strong base in substance with negligible acidity.

-When X- is a stronger base than H20, equilibrium lies to left. HX is a weak acid

-In every acid-base reaction, equilibrium favors transfer of the proton from the stronger acid to the stronger base to form the weaker acid and the weaker base.

-Kc (equilibrium constant) 1 (right)
Know that water auto-ionizes into hydrogen ions and hydroxide ions, expressed by Kw, the ion product of water.
- Kw=[H3O+][OH-]
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