Chemistry Terms and Reactions

These flashcards cover key terms and concepts related to chemical reactions, equations, solubility, gas laws, and thermochemistry.

Chemical equation

A statement using chemical formulas to describe the identities and relative amounts of the reactants and products involved in a chemical reaction.

Chemical reaction

The process by which the atoms of one or more substances are rearranged to form different substances, indicated by changes in temperature, color, odor, and physical state.

Precipitate

A solid produced during a chemical reaction in a solution.

Complete ionic equation

An ionic equation that shows all the particles in a solution as they realistically exist.

Net ionic equation

An ionic equation that includes only the particles that participate in the reaction.

Spectator ion

Ion that does not participate in a reaction.

Product

A substance formed during a chemical reaction.

Reactant

The starting substance in a chemical reaction.

Coefficient

In a chemical equation, the number written in front of a reactant or product that describes the lowest whole-number ratio of the amounts of all reactants and products.

Liquid

A form of matter that flows, has constant volume, and takes the shape of its container.

Aqueous solution

A solution in which the solvent is water.

Solution

A uniform mixture that can contain solids, liquids, or gases, also called a homogeneous mixture.

Solvent

The substance that dissolves a solute to form a solution; the most plentiful substance in the solution.

Solute

One or more substances dissolved in a solution.

Soluble

Describes a substance that can be dissolved in a given solvent.

Insoluble

Describes a substance that cannot be dissolved in a given solvent.

Miscible

Describes two liquids that are soluble in each other.

Immiscible

Describes two liquids that can be mixed together but separate shortly after you cease mixing them.

Unsaturated

A solution that contains less dissolved solute than it has the capacity to hold at a given temperature; more solute can still dissolve.

Single replacement reaction

A reaction in which one element replaces a similar element in a compound (A + BC → AC + B).

Double replacement reaction

A reaction where ions in two compounds exchange partners to form two new compounds (AB + CD → AD + CB).

Dilute

There are more solvent (water) molecules compared to solute particles; to make (a liquid) thinner or weaker by adding water or another solvent.

Saturated solution

Contains the maximum amount of dissolved solute for a given amount of solvent at a specific temperature and pressure.

Super saturated

An unstable solution that contains more dissolved solute than the usual saturation point at a given temperature; excess solute can crystallize out.

Combustion reaction

A chemical reaction that occurs when a substance reacts with oxygen, releasing energy in the form of heat and light.

Synthesis reaction

A chemical reaction in which two or more substances react to yield a single product.

Decomposition reaction

A chemical reaction that occurs when a single compound breaks down into two or more elements or new compounds.

Molar mass

The mass in grams of one mole of any pure substance.

Molecular formula

A formula that specifies the actual number of atoms of each element in one molecule of a substance.

Empirical formula

A formula that shows the smallest whole-number mole ratio of the elements of a compound.

Mole

The SI base unit used to measure the amount of a substance, containing 6.02 × 10²³ representative particles.

Hydrate

A compound that has a specific number of water molecules bound to its atoms.

Avogadro’s number

The number 6.0221367 × 10²³, which is the number of representative particles in a mole.

Thermochemistry

The study of energy changes (heat transfer) that accompany chemical reactions and physical changes.

Heat of reaction

The enthalpy change associated with a chemical reaction, usually reported as ΔH.

Boyle’s Law

States that the volume of a fixed amount of gas held at a constant temperature varies inversely with the pressure.

Charles’ Law

States that the volume of a given mass of gas is directly proportional to its kelvin temperature at constant pressure.

Gay-Lussac’s law

States that the pressure of a fixed mass of gas varies directly with the kelvin temperature when the volume remains constant.

Avogadro’s law

States that equal volumes of gases at the same temperature and pressure contain equal numbers of particles.

Combined gas law

A single law combining Boyle's, Charles's, and Gay-Lussac's laws stating the relationship among pressure, volume, and temperature of a fixed amount of gas.

Ideal gas law

Describes the physical behavior of an ideal gas in terms of pressure, volume, temperature, and number of moles.

Ideal gas constant

An experimentally determined constant whose value in the ideal gas equation depends on the units that are used for pressure.

Molar volume

For a gas, the volume that one mole occupies at 0.00°C and 1.00 atm pressure.

Enthalpy

The heat content of a system at constant pressure.

Calorimeter

An insulated device used to measure the amount of heat released or absorbed during a physical or chemical process.

System

In thermochemistry, the specific part of the universe containing the reaction or process being studied.

Surroundings

In thermochemistry, everything in the universe except the system.

Universe

In thermochemistry, it is the system plus the surroundings.