Chapter 8 Factor Label Method and the Mole

What is Avogadro’s Favorite Novel?

Molby Dick

An equality is a ratio is a conversion factor km = 1 mile 1 pound = kilograms Density of Aluminum = 2.7 g/cm 3 Land speed record = 763 miles/hr

What Do We Know About the Mole

1 mol = 6.02 x _________

What Do We Know About the Mole 1 mol = 6.02 x particles Any equality or ratio can be made into a conversion factor and then used to solve problems with the factor label method.

6.02 x “particles” 1 mole or 1 mole 6.02 x “particles” Note that particles could be atoms, molecules, formula units, ions, etc. Avogadro’s Number as a Conversion Factor

= 6.02 x C atoms = 6.02 x H 2 O molecules = 6.02 x NaCl “molecules” (technically, ionic compounds are not molecules, they are called formula units) A Mole of Particles A Mole of Particles Contains 6.02 x particles 1 mole C 1 mole H 2 O 1 mole NaCl

1 mol Na + = ? 1 mol SO 4 2- = ? 6.02 x Na + ions 6.02 x SO 4 2- ions

What Do We Know About the Mole

1 mol of any substance = it’s gfm

1 mole of C atoms= 12.0 g Gram Formula Mass (Molar Mass) of an atom

1 mole of Mg atoms Gram Atomic Mass (Molar Mass) of an atom 24.3 g 6.02 x Mg atoms

1 mole of Cu atoms Gram Formula Mass (Molar Mass) of an atom 63.5 g 6.02 x Cu atoms

Gram Formula Mass (Molar Mass) of Molecules and Compounds

What is the mass of 1 mol of calcium phosphate? Gram Formula Mass of Ca 3 (PO 4 ) 2 3 x 40.1 = x 31.0 = x 16.0 = = g/mol = 6.02 x Ca 3 (PO 4 ) 2 formula units Gram Formula Mass (Molar Mass) of Molecules and Compounds

List “2” things you know about a mole of H. 1 mole H = 6.02 x H atoms 1 mole H = 1.0g What could we use these equalities to do in a factor label problem?

List “2” things you know about a mole of H 2 O 1 mole H 2 O = 6.02 x H 2 O molecules 1 mole H 2 O = 18.0g

List “2” things you know about a mole of Na 2 O 1 mole Na 2 O = 6.02 x Na 2 O formula units 1 mole Na 2 O = 62.0g

Converting Moles and Grams Aluminum is often used for the structure of light-weight bicycle frames. How many grams of Al are in 8.62 moles of Al? a

1 mole Al = ?

1 mole Al = 27.0 g Al

What are the conversion factors?

1 mole Al = 27.0 g Al 27.0g Al or 1 mol Al 1 mol Al 27.0 g Al What are the conversion factors?

1 mole Al = 27.0 g Al 27.0g Al or 1 mol Al 1 mol Al 27.0 g Al What are the conversion factors? Aluminum is often used for the structure of light-weight bicycle frames. How many grams of Al are in 8.62 moles of Al?

1 mole Al = 27.0 g Al Conversion factors for Al 27.0g Al or 1 mol Al 1 mol Al 27.0 g Al 8.62 moles Al

1 mole Al = 27.0 g Al Conversion factors for Al 27.0g Al or 1 mol Al 1 mol Al 27.0 g Al 8.62 moles Al 27.0 g Al 1 mole Al = 233 g Al

How many Al atoms are in the bicycle frame?

8.62 moles Al

How many Al atoms are in the bicycle frame? 8.62 moles Al 1 mole Al

How many Al atoms are in the bicycle frame? 8.62 moles Al 1 mole Al 6.02 x Al atoms

How many Al atoms are in the bicycle frame? 8.62 moles Al 1 mole Al = 5.19 x Al atoms