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Stoichiometry and the mole- Your new bffl November 2 2 +3 3 -1, 2.009 * 10 3. Objective: SWBAT perform stoichiometric conversions from mole to mass, from mass to mass Catalyst: How many basketballs are in a dozen? How many turkeys are in a dozen? How was your break?
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Stoichiometry and the mole- Your new bfflNovember 22+33-1, 2.009 * 103 • Objective: • SWBAT performstoichiometric conversions from mole to mass, from mass to mass • Catalyst: • How many basketballs are in a dozen? • How many turkeys are in a dozen? • How was your break? *This week… bring scientific calculators if you have them!
Exit Question • What do you need to do to get where you want to be in this class?
Agenda • Catalyst/Welcome Back • Test Review/Tracking/Corrections • OMG! YOUR NEW BFFL! The mole. • Bring back the train tracks • Exit Question
What is a mole to us chemists? • A benign overgrowth of cells because of a failure in mitosis? • NO! But gross… • A rascly little rodent? • NOOOO! • A TV show featuring celebrities? • NOOOOO! • Then WHAT IS IT?????!!!???!?!?!???!!!!
The Mole Think of the term “a dozen”… How many donuts are in a dozen? How many eggs are in a dozen?
The Mole Just like a dozen refers to 12 objects…
The Mole Just like a dozen refers to 12 objects… … the mole refers to …
The Mole Just like a dozen refers to 12 objects… … the mole refers to … 6.02 x 1023 particles
The Mole This number is called Avogadro’s number… 6.02 x 1023602,000,000,000,000,000,000,000
Avogadro’s Number 1 mol = 6.02 x 1023 atoms 1 mol = 6.02 x 1023 molecules Why do YOU think we would do this?
Interpreting Equations 4 Fe + 3 O2 2 Fe2O3 “4 moles of iron react with 3 moles of oxygen gas to produce 2 moles of iron(III) oxide” Coefficients in chemical reactions just refer to how many moles are reacting!
Interpreting Equations C3H8 + 5 O2 3 CO2 + 4H2O “1 mole of propane (C3H8) reacts with 5 moles of oxygen gas to produce 3 moles of carbon dioxide and 4 moles of water”
How many moles needed?(moles – moles) C3H8 + 5 O2 3 CO2 + 4H2O If you start with 10.0 moles of propane (C3H8), how many moles of oxygen gas is needed to fully combust (react)?
How many moles produced? (moles – moles) C3H8 + 5 O2 3 CO2 + 4H2O If you start with 10.0 moles of propane (C3H8), how many moles of carbon dioxide will be produced?
What’s the point of all this? • Key Point #1: Stoichiometry relates the amount of REACTANTS with the amount of PRODUCTS. • It all relates back to the mole… • Scientists use stoichiometry to plan reactions! • And guess what else is coming back….
TRAIN TRACKS!!! • Step 1: • What to what? • Step 2: • Write conversion factor(s) • Step 3: • Train tracks
Avogadro’s Number 1 mol = 6.02 x 1023 atoms How many atoms are in .25 mol N2?
Avogadro’s Number 1 mol = 6.02 x 1023 atoms How many atoms are in .25 mol N2? .25 mol N2
Avogadro’s Number 1 mol = 6.02 x 1023 atoms How many atoms are in .25 mol N2? .25 mol N2 1 mol N2 6.02 x 1023 atoms I guess you can use your calculator for this…
Your turn! Whiteboards. How many atoms are in 1.1 moles of C12H22O11?
OOOH, I want some more train tracks! • Key Point #2: • Molar mass the amount of grams in the mole of a substance. • But Mr. J, how am I ever going to find out this information?
Molar Mass 1 mol C =
Molar Mass 1 mol C = 12 g C
Molar Mass • The atomic weight of an atom is also the molar mass of that atom. • Carbon has an atomic weight of 12.01. • In 1 mole of carbon, there are 12.01 grams. • In 1 mole of sodium, how many grams are there?
Molar Mass 1 mol Na =
Molar Mass 1 mol Na = 23 g Na
Molar Mass-Can you figure out this one?? 1 mol CO2 =
Molar Mass 1 mol CO2 = C = 12 g O = 16 g O = 16 g
Molar Mass 1 mol CO2 = C = 12 g + O = 16 g + O = 16 g
Molar Mass 1 mol CO2 = 44 g CO2 C = 12 g + O = 16 g + O = 16 g
Molar Mass 1 mol KNO3 = K = + N = + O =
Molar Mass 1 mol KNO3 = K = 39 g + N = 14 g + (3) O = 16 g
Molar Mass 1 mol KNO3 = 101 g K = 39 g + N = 14 g + (3) O = 16 g
Molar Mass- Let’s try a problem 1 mol KNO3 = 101 g If we have 3.5 moles of KNO3, how many grams would we have?
Molar Mass 1 mol CH4 = If we have 20 grams CH4, how many moles of CH4 do we have?
Independent Practice • 1, 11, 16… we will go over to show you how to solve this hilarious assignment! • Attach your work on a separate sheet of paper.
Exit Question • How many molecules are in a mole of NH4? • How many grams are there in 2.3 moles of NH4?