catalyst:
DESCRIPTION
Catalyst:. Balance the following chemical equation. Pb (NO 3 ) 2 + AlCl 3 → PbCl 2 + Al(NO 3 ) 3 New seats on front board Objectives: Calculate the moles or grams of a substances in a given equation. Determine the percent composition of elements in a compound. Homework: - PowerPoint PPT PresentationTRANSCRIPT
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Catalyst:Balance the following chemical equation.
Pb(NO3)2 + AlCl3 → PbCl2 + Al(NO3)3
New seats on front boardObjectives:Calculate the moles or grams of a substances in a given equation.Determine the percent composition of elements in a compound.
Homework:C.7/C.10 worksheet
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Warm-up
Balance the following chemical equation.
Pb(NO3)2 + AlCl3 → PbCl2 + Al(NO3)3
1 Pb 12 NO3 3
1 Al 13 Cl 2
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Warm-up
Balance the following chemical equation.
3 Pb(NO3)2 + AlCl3 → PbCl2 + 2 Al(NO3)3
3 Pb 16 NO3 6
1 Al 23 Cl 2
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Warm-up
Balance the following chemical equation.
3 Pb(NO3)2 + 2 AlCl3 → 3 PbCl2 + 2 Al(NO3)3
3 Pb 36 NO3 6
2 Al 26 Cl 6
Converting grams to moles
To convert grams to moles:• Write down your given amount of grams.• Calculate the molar mass.• Put the grams part of the molar mass on
bottom, put the moles part (1 mol) on top.
Converting grams to moles
Ex:• How many moles is 50 grams of magnesium?
• 270 grams of methanol (CH3OH) is how many moles?
Converting moles to grams
To convert moles to grams:• Write down your given amount of moles.• Calculate the molar mass.• Put the grams part of the molar mass on top,
put the moles part (1 mol) on bottom.
Converting moles to grams
Ex:• How many grams is 3 moles of gold?
• .6 moles of baking soda (NaHCO3) is how many grams of baking soda?
Equations and Molar Relationships
CuO (s) + C(s) → Cu(s) + CO2
2 CuO (s) + C(s) → 2 Cu(s) + CO2
2 CuO (s) + C(s) → 2 Cu(s) + CO2
2 formula units CuO
1 atom C 2 atoms Cu 1 molecule CO2
2 mol CuO 1 mol C 2 mol Cu 1 mol CO2
2 CuO (s) + C(s) → 2 Cu(s) + CO2
2 mol CuO = 2 mol Cu2 mol CuO = 1 mol CO2
2 mol CuO = 1 mol C1 mol C = 2 mol Cu1 mol C = 1 mol CO2
2 mol Cu = 1 mol CO2
These will be your conversion factors.
Review & Examples
We have two main places to get conversion factors:• Molar mass (grams <-> moles)• Coefficients (moles <-> moles)
Problem Solving Flow Chart
Use molar mass of X; calculate it using info from periodic table.
Use coefficients from balanced equation.
Use molar mass of Y; calculate it using info from periodic table.
g X → mol X → mol Y → g Y
2 CuO (s) + C(s) → 2 Cu(s) + CO2
We want to produce 35 mol Cu. • How many moles of copper (II) oxide do we
need?
• How many moles of carbon do we need?
2 CuO (s) + C(s) → 2 Cu(s) + CO2
We want to produce 500 g CO2.
• How many moles of copper (II) oxide do we need?
• How many moles of carbon do we need?
2 CuO (s) + C(s) → 2 Cu(s) + CO2
We want to produce 7,345 g Cu.• How many grams of carbon do we need?
• How many grams of CO2 will be produced in the process?
2 CuO (s) + C(s) → 2 Cu(s) + CO2
We want to produce 7,345 g Cu.• How many grams of CuO do we need?
9,194.3 g CuO
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C.9 Percent Composition
Turn to pg. 167.If you had 1 mole of each of the minerals, how many copper atoms would you have in each mole?Which mole would be the heaviest?
Cu2S 159.17 g/mol
CuFeS2 183.54 g/mol
Cu2CO3(OH)2 221.126 g/mol
Which one has the most copper for every gram of the mineral?
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C.9 Percent Composition
• Percent composition gives the percentage (by mass) of an element in a substance.
• If you are given a formula, use the molar mass.
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Cu2S
CuFeS2
Cu2CO3(OH)2
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Ex: A post-1982 penny with a mass of 2.5 g is composed of 2.4375 g zinc and 0.0625 g copper. What is the percent composition of each element?
97.5% zinc2.5% copper
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Ex: Find the percent composition of each element in glucose, C6H12O6