Molar Mass & Avogrados Number

Molar Mass

Phenomenon

• If a solution bubbles, fizzes, and becomes cold after a solute is added, has a chemical reaction occurred?

• Please answer with a statement!

• 3 Minutes

Open Ended

If a solution bubbles, fizzes, and becomes cold after a solute is added, has a chemical reaction occurred?

Counting Atoms

Multiple Choice

In 2 Au(NO3)3 how many oxygen atoms do we have?

• 6

• 3

• 18

• 12

Open Ended

Tell me: How do you think we will find the mass of a chemical compound?

Molar Mass

• The molar mass, also known as molecular weight, is the sum of the total mass in grams of all the atoms that make up a mole of a particular molecule.

• Measured in the unit: grams/mole

How to Calculate Molar Mass

• 1. Count How many atoms you have of each element.

• 2. Find the atomic mass of each element and multiply it by their number of atoms.

• 3. Add up all the masses.

Example: Find the molar mass of Magnesium Nitrate Mg(NO₃)₂!

• Count Number of atoms.

• Find atomic mass from periodic table and multiply it by number of atoms. (use Dynamic Periodic Table)

• Add up all of the masses.

Example: Find the molar mass of Glucose C₆H₁₂O₆!

• Count Number of atoms.

• Find atomic mass from periodic table and multiply it by number of atoms. (use Dynamic Periodic Table)

• Add up all of the masses.

Multiple Choice

What is the Molar Mass for Calcium Hydroxide Ca(OH)₂?

• 74.1 g/mol

• 114.14 g/mol

• 58.09 g/mol

Multiple Choice

Find the Molar Mass for (NH₄)₂SO₄ Ammonium Sulfate!

• 132.16 g/mol

• 114.11 g/mol

• 118.15 g/mol

• 146.17 g/mol

Mole Conversions

Assessment Questions

2 Questions

Open Ended

Explain how to find the molar mass of a compound!

Multiple Choice

Find the molar mass of Sulfur Heptafluoride SF₇!

• 133 g/mol

• 146.06 g/mol

• 165.06 g/mol

• 127.06 g/mol