Chemistry - Chapter 9

The Mole

SI base unit used to measure the amount of a substance

Avogadros Number

1 mole = 6.02 × 10²³ representative particles

Molar Mass

The mass in grams of any mole of any pure substance

The Molar Mass of any element is numerically equivalent to its atomic mass and has the units g/mol

Chemical Formulas

Indicate the number and types of atoms contained in one unit of the compound.

Percent composition

The percent by mass of each element in a compound is the percent composition of a compound

Empirical Formula

Smallest whole number mole ratio of elements

Molecular Formula

Specifies the actual number of atoms of each element in one molecule or formula unit of substance

Always a whole number multiple of the empirical formula

Hydrate

Compound that has a specific number of water molecules bound to its atoms