Download unit 3 homework packet File - District 196 e

CHEMISTRY
Unit 3 Plan – Moles
Name ______________________
Assignments
A)
Mole notes /ws (pg 3-4 in packet)
B)
More mole practice ws (pg 5-6 in packet)
C)
Mole lab
D)
Expt #8 – iron and copper chloride
E)
More TBA
Text Support
 Study pg 45-46 (intro to the mole)
 Study pg 53-55 (molar mass and mole conversions)
 Study pg 250-253 (focus on percent composition on pg 251)
On-Line Text: www.lab-aids.com
Username:
evhs1
Password:
smeyer
(Log in as student in upper right corner. This is a common username and password for all my
chemistry students.)
Learning Targets (I can …)
A)
Differentiate between atoms, molecules, and formula units.
B)
State Avogadro’s hypothesis and discuss its importance in the development of the mole
concept.
C)
State the definitions of a mole.
D)
Determine the molar mass of elements and compounds.
E)
Perform problem solving conversions for moles, grams, atoms, and molecules (operating
the mole train).
F)
Perform chemical reactions, collect data on them, and mathematically determine the mole
relationships involved.
G)
Find the % composition (by mass) of compounds and other substances.
H)
Discuss examples of chemistry outside the classroom.
UNITS AND TERMS TO KNOW AND MEMORIZE
A)
Avogadro’s hypothesis – Equal volumes of gases, measured at the same temperature and
pressure contain equal number of particles.
B)
One mole = 6.0 x 1023
One mole of any gas at STP (standard temperature and pressure) has a volume of
22.4 liters. STP means temperature = 0ºC and pressure = 760 mm Hg or 1.00
atmosphere.
Tentative Schedule
Mon 10/1 The mole, molar mass, and the mole train
Tue
10/2 Qand A
Wed 10/3 Mole Lab
Thu
10/4 Quiz; Expt #8 --- Lab Day #1
Fri
10/5 Expt #8 --- Lab Day #2
Mon
Tue
Wed
10/8 Expt #8 --- Lab Day #3
10/9 Review / practice exam
10/10 Exam #3
Unit #3 packet due
On-line support
 Mr. Guch’s website
http://misterguch.brinkster.net/explains2.html (check out “finding molar masses” and
“mole calculations” sections for excellent coverage of unit 3 topics)
This website will help you out in your quest to understand chemistry. Explanations are at
the introductory level and give some detail --- but not too much. Even the humor is above
average. You need to check this out.
 ChemTeam
www.chemteam.info (see section on “the mole”)
This website may help you in your quest to understand chemistry. Explanations can get
quite involved – depending on the topic. It may be helpful at the introductory level. It will
be especially helpful if you are looking for extra detail.
Chem – Some Unit 3 HW Answers
Scientific Notation Review (pg 3)
1. 3.5 x 10-3
2. 6.09 x 1010
3. 5.6789 x 104
1. 123,000
2. 0.00035
3. 9990
Molar Mass (pg 3)
Answers in sequence for #1-4
1. 17.0 g/mol
2. 100.1 g/mol
Mole Practice (pg 3-4)
Answers in sequence for #1-15
1. 2.4 x 1024 atoms
5. 5.0062 mol
9. 16.0 g/mol
13. 2.1999 mol
2. 2.51 mol
3. 294 g
4. 4900 g
6. 3.4997 mol
7. 2.1076 x 1024 atoms 8. 176 g
10. 96 g
11. 62.0 g/mol
12. 0.8 mol
14. 1.3238 x 1024 molecules
15. 6.7 x 1023 molecules
More Mole Problems (pg 5-6)
Answers scrambled within each number.
#1
236 g
1.8 x 10-6 g
#2
2.6 x 1024 atoms
4.6 x 1021 atoms
22
23
#3
1 x 10
1.3 x 10
3.48 x 1021
-5
#4
2 x 10 mol
0.0578 mol
#5
114 g
#6
1.8 x 1020 molecules
3.3 x 1025 molecules
#7
35 g
3.6 x 1023 molecules
#8
7.8% and 92.2%
42.1%, 6.4% and 51.5%
92.3% and 7.7%
8.1%, 53.7% and 38.3%
3. 44.0 g/mol
4. 182.7 g/mol
27.3 g
460 g
13.6 g
24
2.6 x 10 atoms
2.6 x 1024
(all in molecules)
1320 mol
3.939 mol
3.0 x 10-4 mol
Name
Hour
Mole Notes






A mole is just a number used commonly in chemistry.
There are 6.022 x 1023 particles in a mole. (Avagadro’s Number)
Each element has different sized atoms.
Because of the different sizes, each element has a different mass for 6.022 x 1023
(1 mole) of atoms.
The molar mass (mass of 1 mole) of an element is equal to the atomic mass on
the periodic table. Helium molar mass = 4.003 g/mol
You can find the molar mass of a compound by adding all the masses of each
element in the compound.
o Example: H2O: 2 H (1.0 g/mol) + 1 O (16.0 g/mol) = 18.0 g/mol of water
Scientific Notation Review:
Write the following numbers in scientific notation:
1. 0.0035
_________________________
2. 60900000000
_________________________
3. 56789
_________________________
Write out the following numbers:
1. 1.23 x 105
_________________________
2. 3.5 x 10-4
_________________________
3. 9.99 x 103
_________________________
Molar Mass – Calculate the molar mass of the following compounds.
1. NH3
2.
CaCO3
3. CO2
4.
Ni(NO3)2
Mole Practice
1. How many atoms are present in 4 moles of any element?
2. How many moles are there in 1.51 x 1024 atoms?
3. Determine the mass in grams of 4.5 moles of zinc.
4. Determine the mass in grams of 25 moles of gold.
5. Determine the number of moles in 160.35 g of sulfur.
6. Determine the number of moles of 415.45 g of tin.
7. Determine the number of atoms in the amount of tin from #6.
8. What would be the mass of 4 moles of CO2?
9. What is the molar mass of methane, CH4?
10. What would be the mass of 6 moles of CH4?
11. What is the molar mass of carbonic acid, H2CO3?
12. How many moles of carbonic acid are in 50 grams?
13. How many moles are in 128.57 grams of NaCl?
14. How many molecules (formula units) are in the amount of NaCl from #13?
15. How many molecules (formula units) are in 150 g of CuCl2?
More Mole Problems (Unit #3 Practice)
Name ______________________
All Aboard! Here’s an opportunity to ride the mole train. Show all work and use
appropriate units. You may need additional paper. This worksheet will function as both
an opportunity to solve mole train problems and a review sheet for unit #3. Practice. Ask
questions. Good luck!
1. Calculate the following in grams …
a. 0.43 moles of Cu
b. 1.13 moles of C
c. 2.41 moles of H2SO4
d. 1.2 x 1025 atoms of Na
e. 6.4 x 1015 molecules of AgNO3
2. Calculate the following in atoms …
a. 4.3 moles of Au
b. 4.3 moles of He
c. 0.31 grams of Ca
3. Calculate the following in molecules …
a. 4.3 moles of NaCl
b. 0.02 moles of H2O
c. 21 grams of CaCO3
d. 1.12 grams of K2CrO4
4. Find the amount of moles in …
a. 3.48 x 1022 molecules of CuBr2
b. 231.2 grams of Ni
c. 0.004 grams of AgNO3
d. 7.96 x 1026 atoms of Pb
5. One liter of Kool-Aid contains 2.0 x 1023 molecules of sugar (C12H22O11). What
mass of sugar is present in this sample?
6. A 1000 mL sample of lake water contains 0.0095 grams of dissolved oxygen
molecules (O2). This corresponds to a dissolved oxygen reading of 9.5 ppm.
a. How many moles of dissolved oxygen molecules (O2) are present?
b. How many molecules of dissolved oxygen (O2) are present?
c. How many molecules of water (H2O) are present?(Hint: For water 1000 mL =
1000 g)
7. One liter of ocean water contains 0.60 moles of NaCl.
a. What mass of NaCl is this?
b. How many molecules of NaCl is this?
8. Find the percent composition (by mass) of each element in the following
molecules …
a. C6H6
b. CCl4
c. C12H22O11
d. CBrF3