Moles & Molarity Lecture Notes

These flashcards cover key vocabulary and concepts related to moles, molarity, and related calculations in chemistry.

Mole (mol)

A collective unit used in chemistry to refer to 6.022140857 x 10^23 units of a substance, known as Avogadro’s Constant.

Avogadro's Constant (N)

The number 6.022140857 x 10^23, representing the number of atoms, molecules, or particles in one mole of a substance.

Molarity (M)

A measure of concentration defined as the number of moles of solute per liter of solution.

Dilution

The process of reducing the concentration of a solute in a solution, typically by adding more solvent.

Molecular Mass

The mass of a molecule calculated by adding the atomic masses of its constituent atoms.

Percent Composition

The percentage by mass of each element in a compound.

Hydrate

A compound that has water molecules chemically attached to its ionic components.

Solution

A homogeneous mixture composed of a solvent and one or more solutes.

Concentration

The amount of solute present in a given quantity of solvent or solution, often expressed in terms of molarity.

Reactive Units

Atoms or molecules that participate in a chemical reaction, usually measured in moles.

Atomic Mass

The mass of a single atom of a chemical element, typically expressed in grams per mole (g/mol).

Mass-to-Mass Percentage Concentration (%m/m)

The mass of the solute divided by the total mass of the solution, multiplied by 100.

Volume-to-Volume Percentage Concentration (%v/v)

The volume of the solute divided by the total volume of the solution, multiplied by 100.

Mass-to-Volume Percentage Concentration (%m/v)

The mass of the solute divided by the volume of the solvent, multiplied by 100.

Parts per Million (ppm)

A unit of measurement for concentration, denoting the mass of solute per one million units of solution.

Molar Mass of H2O (water)

18.0153 g/mol, the mass of one mole of water molecules.

Dilution Formula

A formula used to calculate concentration changes: M1V1 = M2V2.

% Water by Mass in Hydrates

Calculated by finding the mass of water in a hydrate and dividing it by the total mass of the hydrate.

Atomic Mass of Lithium (Li)

6.941 g/mol, the mass of one mole of lithium atoms.