Chemical Calculations: The Mole Concept and Chemical Formulas

These flashcards cover essential vocabulary and key concepts related to the mole concept and chemical formulas as outlined in the lecture notes.

Law of Definite Proportions

In a pure compound, elements are always present in the same definite proportion by mass.

Formula Mass

The sum of atomic masses of all the atoms in one formula unit of a substance expressed in atomic mass units (amu).

Significant Figures

Digits in a number that carry meaning contributing to its measurement accuracy.

Mass Percent Composition

The percent by mass of each element in a compound.

Mole

A chemist's counting unit, specifying the amount of a substance in discrete units.

Avogadro’s Number

6.022 x 10^23, representing the number of particles in one mole.

Molar Mass

The mass in grams of one mole of a substance, numerically equal to its atomic or molecular mass.

Empirical Formula

The simplest whole number ratio of elements in a compound.

Molecular Formula

The actual number of atoms of each element in a molecule of the compound.

Purity of Samples

Percent purity is the percent by mass of a specified substance in an impure sample.