Chapter 4 Lecture 2: Precipitation, Acid-Base, Oxidation-Reduction and Gas Forming Reactions

Flashcards covering key definitions and rules related to Gas Forming Reactions, Net Ionic Equations, Oxidation-Reduction Reactions, Oxidation Numbers, and Solution Concentrations (Molarity) from the lecture notes.

Gas Forming Reactions

A double-displacement reaction that has a product that is a gas.

Ionic compound containing S2- + acid

Forms H2S (g) gas.

Ionic compound containing CO32- or HCO3- + acid

Forms H2CO3 (aq), which then decomposes to H2O (l) + CO2 (g).

Ionic compound containing SO32- or HSO3- + acid

Forms H2SO3 (aq), which then decomposes to H2O (l) + SO2 (g).

Ionic compound containing NH4+ + base

Forms NH4OH (aq), which then decomposes to H2O (l) + NH3 (g).

Net Ionic Equation

An equation that shows only the species that participate in the reaction, after eliminating spectator ions from the complete ionic equation.

Strong electrolytes

Substances that completely dissociate into ions in solution, such as strong acids, strong bases, and soluble ionic compounds.

Weak/non-electrolytes

Substances that remain mostly in their molecular form in solution, such as weak acids, weak bases, pure liquids, gases, insoluble ionic compounds, and molecular soluble compounds.

Spectator ions

Ions that are present in both the reactant and product sides of a complete ionic equation and do not participate in the actual reaction.

Oxidation-Reduction Reaction

A reaction in which electrons are transferred from one species to another.

Oxidation Number

A number assigned to each element in a substance based on a series of rules, indicating the charge an atom would have if all bonds were ionic.

Oxidation number of an atom in its elemental state

Zero.

Oxidation number of monatomic ions

Equal to the charge of the ion.

Oxidation number of Fluorine (F)

-1 in combination with other elements.

Oxidation number of Oxygen (O)

-2, generally (with some exceptions like peroxides).

Oxidation number of Hydrogen (H)

+1 with a nonmetal and -1 with a metal, generally.

Sum of oxidation numbers in a species

Must equal the charge of the species (zero for a neutral compound, the ion's charge for a polyatomic ion).

Oxidation

The loss of electrons by a substance in a reaction.

Reduction

The gain of electrons by a substance in a reaction.

Concentration

A measure of how much of a pure substance (solute) is dissolved in a solvent, forming a solution.

Molarity (M)

Moles of solute in exactly 1 liter of a solution. Units: mol/L or mol solute / 1 L solution.