chem unit 4 review

Collision Theory

A set of principles stating that reacting particles must collide with sufficient kinetic energy and the correct orientation to form products.

Activation Energy

The minimum amount of energy required for atoms, molecules, or ions to undergo a chemical change.

Effective Collisions

Collisions between reactants that result in the breaking of original bonds and the formation of new bonds in products.

Factors Affecting Reaction Rate

Surface area, concentration or pressure, temperature, nature of reactants, and presence of a catalyst.

Catalyst

A substance that increases the rate of a chemical reaction without undergoing any permanent chemical change.

Chemical Equation

A symbolic representation of all substances involved in a chemical change.

Balanced Chemical Equation

An equation in which the number of each type of atom is conserved on both sides of the reaction.

Endothermic Reaction

A reaction where energy absorbed is greater than energy released.

Exothermic Reaction

A reaction where energy released is greater than energy absorbed.

Synthesis Reaction

A reaction in which two or more substances combine to form a single product.

Decomposition Reaction

A reaction where a single compound breaks down into two or more products.

Single-Replacement Reaction

A reaction in which atoms of one element replace the atoms of a second element in a compound.

Double-Replacement Reaction

A reaction involving the exchange of positive ions between two compounds.

Combustion Reaction

A reaction in which an element or compound reacts with oxygen, often producing heat or light.

Redox Reactions

Reactions that involve the transfer of electrons between reactants.

Oxidation Number

A number assigned to an element in a compound that reflects its electron gain or loss.

Reduction

The gain of electrons by a reactant during a chemical reaction.

Oxidation

The loss of electrons by a reactant during a chemical reaction.

LEO GER

A mnemonic that stands for Loss of Electrons is Oxidation, Gain of Electrons is Reduction.

Spectator Ions

Ions that do not participate in the formation of a product in a chemical reaction.

Net Ionic Equation

An equation that represents only the species undergoing change in a reaction, excluding spectator ions.

Neutralization Reaction

A double replacement reaction that forms water and a salt.

Dissociation Equation

An equation representing how ionic compounds separate into their constituent ions when dissolved in water.

Solubility Rules

Guidelines that predict the solubility of ionic compounds in water.

Precipitate

An insoluble solid that forms when two aqueous solutions react.