Big Idea: Matter & Atoms
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The Mole
Stoichiometry
Limiting Reactants
Percent Yield
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Avogadro’s Number (NA)
◦ 6.022 𝑥 1023 𝑎𝑡𝑜𝑚𝑠/𝑚𝑜𝑙
The mole…
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1 mol of Ne atoms = 6.022 𝑥 1023 𝑎𝑡𝑜𝑚𝑠 𝑜𝑓 𝑁𝑒 = 20.18 g
1 mol of Cl- ions = 6.022 𝑥 1023 𝑎𝑡𝑜𝑚𝑠 =35.45 g
The mole is a fundamental unit for counting
particles on the macroscopic level.
 It allows us to draw quantitative connections
between macroscopic experiments & atomic level
chemical processes.
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Molecular weight = 12.01 amu + 2(16.00 amu)
= 44.01 amu/CO2 molecule
= 44.01 g/mol CO2
1 mol CO2 molecules = 6.022 x 1023
molecules = 44.01 g
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How many moles of NaCl are there in 48.0 g
of NaCl?
Now many grams of C2H6 are there in 18.7
moles of C2H6?
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How many water molecules are contained
within 56.0 g pure sample of water?
How many hydrogen atoms are contained
within 56.0 g pure sample of water?
gfm=gram formula mass…
Same as molar mass
C=12.01 amu
H=4(1.01) amu
O=4(16.00) amu
12.01 amu
4.04 amu
64.00 amu
C=12.01 amu
12.01 amu
H=4(1.01) amu
4.04 amu
O=4(16.00) amu 64.00 amu
80.05 amu
80.05 amu
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What mass of water is produced when a car
burns 264.4 g of methane gas?
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Step 1: Write the balanced chemical equation.
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Step 2: Convert to Mass of Water
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How many grams of carbon dioxide and iron
are produced when 114.0 g of carbon
monoxide gas is added to a vessel containing
excess hot iron (III) oxide?
Step 1: Write balanced chemical equation.
Step 2: Calculate masses of carbon dioxide &
iron.
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Calculate the mass of solid sodium
bicarbonate needed to produce 32.0 g of
sodium carbonate in a decomposition
reaction.
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If you have set quantities of two different
reactants, one will get used up & some
amount of the other will be left over.
Limiting Reactant
◦ The reactant that is used up limits how far the
reaction will proceed.
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Excess Reactant
◦ The reactant that has some left over when the
reaction is complete.
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What is the limiting reactant when 28.0 g of
glucose reacts with 14.0 g of oxygen gas in a
combustion reaction?
What is the mass of carbon dioxide
produced?
𝐴𝑐𝑡𝑢𝑎𝑙 𝑌𝑖𝑒𝑙𝑑 𝑓𝑟𝑜𝑚 𝐿𝑎𝑏

𝑇ℎ𝑒𝑜𝑟𝑒𝑡𝑖𝑐𝑎𝑙 𝑌𝑖𝑒𝑙𝑑 𝑓𝑟𝑜𝑚 𝐸𝑞𝑛
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× 100% = 𝑃𝑒𝑟𝑐𝑒𝑛𝑡 𝑌𝑖𝑒𝑙𝑑
Calculate the percent yield if 15.0 grams of
carbon dioxide were produced in lab from the
previous example.