Mastering Chemical Reactions and Equations

Physical Change

A change in properties without altering chemical composition.

Chemical Change

A process where substances convert into different substances with new properties.

Intermolecular Forces (IMFs)

Forces that must be overcome during a physical change.

Intramolecular Bonds

Bonds that are broken and formed during a chemical change.

Examples of Physical Change

Phase changes such as melting, boiling, and sublimation.

Evidence of Chemical Change

Signs such as precipitate formation, color change, gas evolution, or temperature change.

Precipitate

A solid formed when two liquids react.

Net Ionic Equation

An equation that shows only the species participating in a reaction, removing spectator ions.

Law of Conservation of Mass

Matter cannot be created or destroyed; must balance chemical equations.

Reactants

Substances present before the reaction, located on the left side of the equation.

Products

New substances formed in a reaction, located on the right side of the equation.

Coefficients

Numbers indicating the mole ratio of reactants and products in a balanced equation.

Spectator Ions

Ions that do not participate in the actual reaction and appear unchanged.

Complete Ionic Equation

An equation showing all soluble ionic compounds dissociated into their ions.

Strong Electrolytes

Compounds that dissociate completely in solution.

Weak Acids/Bases

Compounds that do not completely dissociate in solution (e.g., acetic acid, hydrofluoric acid).

Aqueous State (aq)

Substances dissolved in water.

Gas State (g)

Substances in gaseous form.

Liquid State (l)

Substances in liquid form.

Solid State (s)

Substances in solid form or precipitates.

Molecular Equation

An equation showing the reaction with complete molecular formulas.

Acetic Acid

A weak acid often incorrectly simplified in net ionic equations.

Dissolution

The process of a substance (like salt) being dissolved in a solvent (like water).

Limiting Reactant

The reactant that is entirely consumed in a reaction, limiting the amount of product formed.

Excess Reactant

The reactant that remains after the reaction has completed.

Phase Changes

Transformations between solid, liquid, and gas states without chemical composition change.

Chemical Reaction Signs

Indicators of a reaction such as color change, gas production, and formation of precipitates.