Introduction to the Mole

Common Core Connection Objectives: Today I will be able to: Calculate the formula mass of a compound Apply the mole conversion factor to calculations relating to the quantity of atoms in a sample Informal assessment – monitoring student interactions as they complete the practice Formal assessment – analyzing student responses to the practice and the exit ticket Common Core Connection Make sense of problems and persevere in solving them Reason abstractly and quantitatively Build strong content knowledge

Lesson Sequence Evaluate: Warm-Up Explain: Formula Mass Elaborate: Formula Mass Practice Explain: Intro to the Mole Notes Elaborate: Mole Practice Evaluate: Exit Ticket

Warm-Up How would you calculate the mass of water using the periodic table?

Objective Today I will be able to: Calculate the formula mass of a compound Apply the mole conversion factor to calculations relating to the quantity of atoms in a sample

Homework Finish classwork

Agenda Warm-Up Formula Mass Notes Formula Mass Practice Intro to the Mole Notes Mole Practice Exit Ticket

Formula Mass Notes

Formula Mass of Compounds The formula mass of the elements can be used to find the molar mass of a compound Example: Water (H2O) Element Number Mass (g/mol) H 2 1.01 O 1 16.0 Total mass of Water 18.0

Introduction to the Mole

How can we make a large quantity easier to count? Example Instead of counting eggs individually we can count the number of dozens 1 dozen = 12 eggs OR 12 eggs = 1 dozen If a baker buys 6 dozen eggs, how many eggs does he have? 6 dozen 1 12 eggs 1 dozen = 72 eggs x

The Mole Atoms are too small and too numerous to count so we needed to develop a constant value of atoms to make it more reasonable to work with. The Mole (Avogadro's Number) 6.02 x 1023 602,000,000,000,000,000,000,000

Example If you took a mole of dollar bills and placed them next to each other around the circumference of the earth, they would go around the earth how many times? 2.34 x 1015 That’s Huge! Bring paper with dollar calculation

Particles = Atoms, Molecules, Formula Units 1 Mole = 6.02 x 1023 Particles Particles = Atoms, Molecules, Formula Units

We will use this when we get to the gas law unit 1 mole = 22.4 Liters We will use this when we get to the gas law unit

Example 1 How many formula units of AgCl are in 2.0 moles of AgCl?

Example 2 How many Mg atoms are in 0.5 moles of Mg?

Converting from Mass to Moles Atomic mass is based on the mass of one mole of an element or compound 1 mole = atomic mass unit of an element or compound in grams (molar mass) Example: Carbon 1 mol of carbon = 12 grams carbon 12 grams of carbon has 6.02 x 1023 atoms of carbon

Molar Mass What is the mass of one mole of Chlorine? 35.45 grams of chlorine = 1 mole of chlorine 35.45 grams of chlorine has 6.02 x 1023 atoms This is the Molar Mass of an element It can be used as a conversion factor! 35.45 grams Cl 1 mole Cl 1 mole Cl 35.45 grams Cl OR

Molar Mass of Compounds The formula mass of the elements can be used to find the molar mass of a compound Example: Water (H2O) 18.0 grams of water = 1 mole of water 18.0 grams of water has 6.02 x 1023 molecules of water Element Number Mass (g/mol) H 2 1.01 O 1 16.0 Total mass of Water 18.0

The Mole If there was 20.0 g of iron, how many moles in that amount? 20.0 g Fe 1 x 1 mol 56 g Fe = .357 mol Fe

The Mole If you have 10.0 g of water, how many molecules in that amount? 10.0 g H2O 1 6.02 x 1023 molecules 1 mol 1 mol 18 g H2O x x = 3.34 x 1023 molecules of H2O

The Mole If you have 25.0 g of copper (II) sulfate, CuSO4, how many formula units are in that mass? 1 mol 160 g CuSO4 6.02 x 1023 formula units 1 mol 25.0 g CuSO4 1 x x 9.41 x 1022 formula units of CuSO4 =

Mole Practice Complete the practice at your desk. Ask Ms. Ose for help if you have questions

Exit Ticket How many moles are in 6.02 x 1025 molecules?