Molar Conversions (Dimensional Analysis)

Lesson Overview:

1. What is a mole?

2. Who is Avogadro?

3. Molar Mass

4. Practice Questions

5. Molar Conversions

6. Practice Questions

what is a mole?

-The mole (mol) is the SI measure of quantity
of a chemical entity.

• The amount of a substance that contains as
  many particles as there are atoms.

• 1 mole = 6.02 x 10

• 6.02 x 10 is called Avogadro’s Number

  Chemical Entities:

  • Atoms

  • Electrons

  • Protons

  • Molecules

  • Particles

  • ions

Who is Avogadro?

• Italian chemist Amedeo Avogadro (1776–1856)

• Avogadro correctly hypothesized that equal volumes of gases, at the same temperature and pressure, contain equal numbers of molecules.

Molar Mass:

• The mass in grams of one mole of a substance.

• Measured in g/mol

• Use atomic mass to calculate molar mass.

How to calculate Molar Mass:

Step 1: Find the atomic mass of each atom involved in the chemical compound.

Step 2: Multiply the atomic mass by the amount of atoms of that element present in the chemical compound.

Step 3: Add together the sums. Your new unit is g/mol.

Mole Conversions:There are 4 main conversions using the mole that I would like you to familiarize yourself with:

• moles grams

• grams moles

• moles particles

• particles moles

Moles to Grams

Multiply the moles of the substance by the Molar Mass.

Grams to Moles

Multiply the moles of the substance by the Molar Mass.

Moles to Particles

Multiply the moles of the substance by the Molar Mass.

Particles to Moles

Divide the number of particles by Avogadro’s Number.