Acid-Base Theories and Redox Reactions Overview

Arrhenius Acid

Produces H⁺ in solution

Arrhenius Base

Produces OH⁻ in solution

Bronsted-Lowry Acid

Proton (H⁺) donor

Bronsted-Lowry Base

Proton (H⁺) acceptor

Conjugate Acid

Base + H⁺

Conjugate Base

Acid - H⁺

Amphoteric

Can act as both an acid and a base (e.g., H₂O)

Strong Acid

Completely dissociates in solution

Weak Acid

Partially dissociates in solution

Neutralization

Acid + Base → Salt + Water

pH

-log[H⁺]

pOH

-log[OH⁻]

pH + pOH

Equals 14

[H⁺][OH⁻]

1.0 × 10⁻¹⁴

MaVa = MbVb

Used to calculate titration endpoints (monoprotic)

OIL RIG

Oxidation Is Loss, Reduction Is Gain

LEO the lion says GER

Loss of Electrons = Oxidation; Gain = Reduction

Oxidation

Loss of electrons; oxidation number increases

Reduction

Gain of electrons; oxidation number decreases

Oxidation Number

Charge assigned to an atom to track electrons

Rules for Oxidation Numbers

Elemental = 0; Group 1 = +1; Group 2 = +2; O = -2; H = +1

Half-Reaction

An equation showing only oxidation or only reduction

Oxidation Half-Reaction

Electrons on product side (e.g., Zn → Zn²⁺ + 2e⁻)

Reduction Half-Reaction

Electrons on reactant side (e.g., Cu²⁺ + 2e⁻ → Cu)

Steps to Balance Redox

1) Assign Ox #s, 2) Half-reactions, 3) Balance mass/charge, 4) Combine

Acidic Redox Balancing

Use H₂O for O, H⁺ for H, then electrons

Basic Redox Balancing

Balance as if acidic, then add OH⁻ to neutralize H⁺

Voltaic (Galvanic) Cell

Spontaneous; generates electricity; oxidation at anode

Electrolytic Cell

Non-spontaneous; uses electricity; oxidation at anode

Anode

Where oxidation occurs

Cathode

Where reduction occurs

Table J

Reactivity series; higher = more reactive

Buffer

Resists changes in pH

Binary Acid

Contains H + one other nonmetal (e.g., HCl)

Oxyacid

Contains H, O, and another element (e.g., HNO₃)

Titration

Technique to find unknown concentration of an acid or base

Indicator

Substance that changes color at endpoint of titration

Kw

1.0 × 10⁻¹⁴ (autoionization constant of water)

Solution A pH = 2.5 vs B pH = 5

A is 316× more acidic (10^2.5)