C.P. Chemistry
Test Chapter 7
Study Guide
The Mole and Chemical Quantities
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define “mole” as a unit of measurement.
describe how Avogadro’s number is related to a mole of a
substance.
calculate the mass of a mole of a substance using the periodic
table.
define a “mole” in terms of volume.
convert among measurements of mass, volume and number of
particles using the mole.
explain what is meant by the percent composition of a
compound.
determine the empirical and molecular formulas for a
compound from mass percent and actual mass data.
explain what a hydrate is and how its name reflects its
composition.
determine the formula for a hydrate from laboratory data.
C.P. Chemistry
Review Sheet
Name: ______________________
Date: _______________________
Chapter 7: The Mole and Chemical Quantities
Please answer each question. Show all work. Remember sig figs and units.
1) What is the molar mass of the following: (you must show work for compounds)
MgCl2 ______________
Rn _________________
C11H22O12 _____________
H3PO4 _________________
(NH4)2SO4 ______________
Co ____________________
2) Determine the percent composition of the elements in the following compounds
a. N2O
b. Ca(OH)2
c. C14H10O4
d. C7H5NO3S
Fill in the blanks in chart by using the appropriate computation. Please show
all work in the space provided and remember units.
Compound
Number of
Moles
Li(OH)
5.57 moles
C5H11O7
CuSO4
34.56 moles
h)
a)
Mass
b)
183.11 g/mole
d)
Mg2(PO4)3
Molar Mass
f)
c)
654.7 grams
100 grams
WORK:
a)
f)
b)
g)
c)
h)
d)
i)
e)
j)
e)
5.66 * 1021 atoms
g)
i)
Representative
Particles
j)
3) Name the following hydrates or give the formula:
a. Na2CO3 * 10H2O ____________________________
b. BaCl2 * 4H2O ________________________________
c. CaSO4 * 2H2O ________________________________
d. Copper Sulfate trihydrate _________________________
e. Magnesium Chloride heptahydrate __________________
4) Calcium bromide is a compound used in the manufacture of fire extinguishing
materials. Analysis reveals that calcium bromide contains 20% calcium and
80% bromine. Calculate the empirical formula.
5) What is the empirical formula of a compound if the percent composition is
aluminum 15.77%, sulfur 28.11% and oxygen 56.12%?
6) If the molar mass of a compound is 108g/mole and it contains 4.02g N and
11.48 g O, what is its molecular formula?
7) The molar mass of a compound is 92g/mole. Analysis of the compound shows
0.608g of N and 1.388g O. What is the molecular formula of this compound?
8) Beryl is a hard mineral which occurs in a variety of colors. A sample contains
2.52 g Be, 5.01g Al, 15.68g Si, and 26.79g O. Determine the empirical formula
for Beryl.
9) Determine the molecular formula for ibuprofen, a common headache remedy.
Ibuprofen contains a percent composition of 75.7% C, 8.80% H and 15.5% O
and has a molar mass of 206g/mole.
10) What is the density of O2 at STP?
11) 3 L of a gas has the mass of 2.00 g. What is the molecular mass?
12) What volume does 22.0 g of CO2 at STP occupy?