Patricia Rozema and City Artists Rozema: General Intro. “ In the Various Restaurants ”
Name: Hour: Teacher: ROZEMA / CHEMISTRY The Mole · Approximately how sticks of chalk would there...
Transcript of Name: Hour: Teacher: ROZEMA / CHEMISTRY The Mole · Approximately how sticks of chalk would there...
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Name: ___________________________________________ Hour: _________ Teacher: ROZEMA / CHEMISTRY
The Mole
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Summary Notes
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Summary Notes
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Molar Mass To help you better visualize the enormous size of Avogadro's number,
6.02 x 1023, consider the following analogies:
1. If we had a mole of rice grains, all the land area of the earth would be
covered with rice to a depth of about 75 meters!
2. One mole of marshmallows (standard 1 in3 size) would cover the United
States to a depth of 650 miles.
3. If the Mount St. Helens eruption had released a mole of particles the size of sand grains, the entire state of Washington would have been buried to a depth equal to the height of a 10-story building.
4. A mole of basketballs would just about fit perfectly into a ball bag the size of
the earth.
Check out the teacher demo. He’s a super-fast counter and measured out these substances before class today.
Write down the quantity of each substance as an equality.
Copper, Cu: 1 mole Cu = _____________________________________
Aluminum, Al: _________________________________________________
Water, H2O: _________________________________________________
3. How was the mass of one mole of water determined? Follow your teacher’s lead to calculate below:
4. The quantities you wrote down in question #3 are called molar masses. After learning how to determine the
molar mass of chemical compounds, and write them as equalities. Be sure to include a number, unit, and
label on each side of your equality. (space is given below for calculations)
Magnesium, Mg: 1 mole Mg = ____________________________________
Iron, Fe: _________________________________________________________
Oxygen gas, O2: __________________________________________________
Methane gas, CH4: _______________________________________________
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Write out the molar masses of some of these more complicated compounds. For compounds where elements
are written in parentheses, the elements in the parentheses have to be multiplied by the subscript outside of
the parentheses.
Example: 1 mole of Mg(NO3)2 has 1 mole Mg, 2 moles N, and 6 moles O.
To calculate the molar mass of Mg(NO3)2:
Mg: 24.31 g
N: 14.01 x 2 = 28.02 g
O: 16.00 x 6 = 96.00 g
Total mass = 24.31 + 28.02 + 96.00 = 148.33 g
Molar mass equality: 1 mol Mg(NO3)2 = 148.33 g Mg(NO3)2
5. Calculate the molar mass of glucose, C6H12O6 here (SHOW WORK!)
C: _____________ Total mass:
H: _____________
O: _____________
Molar mass equality (be sure to write a number, unit, and label):
____________________ = _____________________
Draw a particle diagram for
Mg(NO3)2
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6. Calculate the molar mass of aluminum nitrate, Al(NO3)3 here (SHOW WORK!)
Al: _____________ Total mass:
N: _____________
O: _____________
Molar mass equality (be sure to write a number, unit, and label):
____________________ = _____________________
7. Calculate the molar mass of magnesium hydroxide, Mg(OH)2 here (SHOW WORK!) Mg: _____________ Total mass:
O: _____________
H: _____________
Molar mass equality (be sure to write a number, unit, and label):
____________________ = _____________________
8. Calculate the molar mass of sodium chloride, NaCl here SHOW WORK! Set up individual elements as you
did for problems 5-7.
Molar mass equality (be sure to write a number, unit, and label):
____________________ = _____________________
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9. Calculate the molar mass of sodium bicarbonate, NaHCO3 here SHOW WORK!
Molar mass equality (be sure to write a number, unit, and label):
____________________ = _____________________
10. Calculate the molar mass of calcium phosphate, Ca3(PO4)2 here SHOW WORK!
Molar mass equality (be sure to write a number, unit, and label):
____________________ = _____________________
11. Calculate the molar mass of ammonium sulfate, (NH4)2SO4 here SHOW WORK!
Molar mass equality (be sure to write a number, unit, and label):
____________________ = _____________________
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12. Calculate the molar mass of aluminum carbonate, Al2(CO3)3 here SHOW WORK!
Molar mass equality (be sure to write a number, unit, and label):
____________________ = _____________________
13. Calculate the molar mass of gallium oxalate, Ga2(C2O4)3 here SHOW WORK!
Molar mass equality (be sure to write a number, unit, and label):
____________________ = _____________________
14. Calculate the molar mass of barium acetate, Ba(C2H3O2)2 here SHOW WORK!
Molar mass equality (be sure to write a number, unit, and label):
____________________ = _____________________
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Moles Lab
1. Find the molar mass of iron, Fe.
Molar mass equality (be sure to write a number, unit, and label):
____________________ = _____________________
Weigh out a mole of iron in nails. Approximately how many nails are there in one mole of iron?
2. Find the molar mass of water, H2O.
H = ___________________
O = ___________________
Molar mass equality (be sure to write a number, unit, and label):
____________________ = _____________________
Place an empty graduated cylinder on top of the scale. ZERO the scale! Then measure out the
grams of water into the graduated cylinder. Approximately how many mL of water are there
in one mole of water?
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3. Find the molar mass of lead, Pb.
Molar mass equality (be sure to write a number, unit, and label):
____________________ = _____________________
Weigh out a mole of lead shot. APPROXIMATELY how many pieces of lead shot are there in a
mole of lead? PLEASE don’t sit here and count the pellets. Maybe count out the number it
takes to get to about 10% of the mass (20.7 grams) and then multiply by 10.
4. Find the molar mass of Epsom salt, MgSO4.
Mg = ____________________
S = ______________________
O = ______________________
Molar mass equality (be sure to write a number, unit, and label):
____________________ = _____________________
Place an empty weighing boat on top of the scale. ZERO the scale! Then measure out the grams
of Epsom salts that are in one mole of MgSO4. About how many feet could you soak with this
amount of salt?
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5. Find the molar mass of table salt, NaCl.
Na = ____________________
Cl = ______________________
Molar mass equality (be sure to write a number, unit, and label):
____________________ = _____________________
Place an empty weighing boat on top of the scale. ZERO the scale! Then measure out the grams
of table salt that are in one mole of NaCl. How many salt shakers do you think you could fill
with this amount of salt?
6. Find the molar mass of baking soda, NaHCO3.
Na = ____________________ H = ______________________
C = ______________________ O = ______________________
Molar mass equality (be sure to write a number, unit, and label):
____________________ = _____________________
Place an empty weighing boat on top of the scale. ZERO the scale! Then measure out the grams
of baking soda that are in one mole of NaHCO3.
Use the teaspoon to see how many teaspoons there are in one mole of baking soda (measure it
back into the original container). If it takes 1 teaspoon of baking soda to make 4 dozen
cookies, how many dozen cookies can you make with one mole of baking soda?
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7. Find the molar mass of chalk, CaCO3.
Ca = ____________________ C = ______________________
O = ______________________
Molar mass equality (be sure to write a number, unit, and label):
____________________ = _____________________
Approximately how sticks of chalk would there be in one mole of chalk, CaCO3?
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Conservation of Matter
1a. Hydrogen sulfide gas, H2S, which smells like rotten eggs, burns in air (excess amounts) to produce sulfur
dioxide, SO2, and water. If this reaction happened a mole of times, determine the number of grams of each
reactant and product that are used or produced.
Equation: 2 H2S(g) + 3 O2 (g) 2 SO2(g) + 2 H2O(g)
Total mass of reactants: Total mass of products:
2. Ammonia, NH3, for fertilizer is made by causing hydrogen gas and nitrogen gas to react at high
temperature and pressure. If this reaction happened a mole of times, determine the number of grams of each
reactant and product that are used or produced.
1 N2(g) + 3 H2(g) 2 NH3(g)
Total mass of reactants: Total mass of products:
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3. The poison gas phosgene, COCl2, reacts with excess amounts of water in the lungs to form hydrochloric
acid, HCl, and carbon dioxide. If this reaction happened a mole of times, determine the number of grams of
each reactant and product that are used or produced.
1 COCl2 (g) + 1 H2O (l) 2 HCl (aq) + 1 CO2 (g)
Total mass of reactants: Total mass of products:
4. Aluminum burns in air (excess) to produce aluminum oxide, Al2O3.
Suppose someone takes 10.0 grams of aluminum and reacts it with 8.9 grams of oxygen gas. How many grams
of Al2O3 do you think will be made?
Equation: 4 Al (s) + 3 O2(g) 2 Al2O3 (s)
How did you arrive at your answer?
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5. Potassium chlorate, KClO3, decomposes in extreme heat to form oxygen gas and potassium chloride.
Suppose someone forms 12.0 grams of KCl and 7.7 grams of oxygen gas. How many grams of KClO3 would the
person need to start with to produce these quantities?
Equation: 2 KClO3 (s) 3 O2(g) + 2 KCl (l)
How did you arrive at your answer?
6. Iron metal and oxygen combine to form the magnetic oxide of iron, Fe3O4.
Suppose someone takes 15.0 grams of iron and reacts it with 5.7 grams of oxygen gas. How many grams of
Fe3O4 do you think will be made?
Equation: 3 Fe (s) + 2 O2(g) 1 Fe3O4 (s)
How did you arrive at your answer?
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7. Suppose you have the same reaction as you had in #6. Now, someone takes 22.0 grams of iron and reacts it
with 20.0 grams of oxygen gas. He finds that 11.6 grams of oxygen are left over after the reaction is complete.
Equation: 3 Fe (s) + 2 O2(g) 1 Fe3O4 (s)
a) How many grams of oxygen were used up in this reaction? Show how you got this value.
b) How many grams of Fe3O4 did you produce in this reaction? Show how you got this value.
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6. Propane, C3H8, is commonly used as a fuel in gas grills. It burns in air to form carbon dioxide and water.
Suppose you have 50.0 grams of propane, and react it with 300.0 grams of oxygen. After the reaction, you find
that you have 118.7 grams of oxygen remaining. You also find that you have produced 149.7 grams of CO2.
Equation: 1 C3H8 (g) + 5 O2 (g) 3 CO2 (g) + 4 H2O
a) How many grams of oxygen were used up in the reaction? Show how you got this value.
b) How many grams of water did you produce? Show how you got this value.