Moles and Molar Mass Review

Moles Day 2

Multiple Choice

What is the mass of 2 moles of sodium thiosulfate (gram formula mass = 158 g/mol).

What is the mass?

• 2 mol

• 159 g/mol

• unknown

Multiple Choice

What is the mass of 2 moles of sodium thiosulfate (gram formula mass = 158 g/mol).

What is the number of moles?

• 2 mol

• 158 g/mol

• unknown

Multiple Choice

What is the mass of 2 moles of sodium thiosulfate (gram formula mass = 158 g/mol).

What is the gram formula mass?

• 2 mol

• 158 g/mol

• unknown

Open Ended

What is the mass of 2 moles of sodium thiosulfate (gram formula mass = 158 g/mol)?

mass = mass

mol = 2

gfm = 158

moles = mass/gfm

Steps to finding the moles when gram formula mass is not given

• Step 1: Find the gram formula mass

• Step 2: Locate and Label your knowns

• Step 3: Determine the unknown

• Step 4: Substitute

• Step 5: Solve

Example 1:

What is the mass of 3 moles of potassium nitrate [KNO3]?

Step 1: Find the gram formula mass

Example 1:

• What is the mass of 3 moles of potassium nitrate [KNO3]?

• Step 2: Locate and Label the knowns

• Step 3: Determine the unknown

• Step 4: Substitute

• Step 5: Solve.

Example 2:

What is the mass of 0.75 moles of aluminum oxide [Al2O3]?

Step 1: Find the gram formula mass

Multiple Choice

Example 2:

What is the mass of 0.75 moles of aluminum oxide [Al2O3].

gfm = 102 g/mol

What is the mass?

• 0.75 mol

• 102 g/mol

• unknown

Multiple Choice

What is the mass of 0.75 moles of aluminum oxide [Al2O3].

gfm = 102

What is the number of moles?

• 0.75 mol

• 102 g/mol

• unknown

Multiple Choice

What is the mass of 0.75 moles of aluminum oxide [Al2O3].

gfm = 102

What is the gram formula mass?

• 0.75 mol

• 102 g/mol

• unknown

Example 2: What is the mass of 0.75 moles of aluminum oxide [Al2O3].

• mol = 0.75 mol

• gfm = 102

• mass = mass