CHEMISTRY-CP
MIDTERM PROBLEM REVIEW
QUESTION 1
Write 0.0005321 in scientific notation.
Answers to problem Midterm Math Review Sheet #1
3.54 x 10-3
4.5 x 105
QUESTION 2
Write 2.33 x 105 in regular notation.
Answers to problem Midterm Math Review Sheet #1
107000
0.0069
QUESTION 2
How many grams in 0.32 kilograms?
Answers to problem Midterm Math Review Sheet #2
6000 g
0.5 s
QUESTION 4
How many significant digits are in the
following measurement: 0.0230430 grams
Answers to problem Midterm Math Review Sheet #3
0.00560 = 3
5090. = 4
400 = 1
6.00 x 102 = 3
QUESTION 5
Calculate the answer to this problem &
express it to the proper # of sig figs.
501.2 x 623.2 x 2.10 x 0.0050
Answers to problem Midterm Math Review Sheet #4
19
4x105 (or 400000)
460 (or 4.6x102)
7.7 x 10-4
QUESTION 6
A piece of metal has the following dimensions:
length = 1.25 cm; width = 1.00 cm; height = 2.34 cm.
The mass of the metal is 26.2 g. What is the density of the
metal?
Answers to problem Midterm Math Review Sheet #5
0.5 g/mL
0.06 g
QUESTION 6
What is the molar mass of Mg(OH)2?
Answers to problem Midterm Math Review Sheet #6
44.01 g/mol
179.87 g/mol
96.11 g/mol
249.72 g/mol
QUESTION 7
What is the percent composition by mass of
oxygen in AlPO4?
Answers to problem Midterm Math Review Sheet #7
11.2% H & 88.8% O
39.8% Cu, 20.1% S, 40.1% O
82.2% N & 17.8% H
QUESTION 8
How many grams of water are in 22.0 g of
MgCl2*2H2O?
Answers to problem Midterm Math Review Sheet #7
3.6 g H2O
QUESTION 9
1,6-diaminohexane is used to make nylon. What
is the empirical formula of this compound if it is
62.1% C, 13.8% H and 24.1% N?
Answers to problem Midterm Math Review Sheet #8
CaCl2
CeI3
QUESTION 10
What is the molecular formula of ethylene glycol,
antifreeze, if its molar mass is 62 g/mol and its
empirical formula is CH3O?
Answers to problem Midterm Math Review Sheet #8
N2H4
QUESTION 11
How many moles are in 123 grams of lead
(IV) chloride?
QUESTION 12
How many formula units are in 22.3 grams of
magnesium hydroxide?
Answers to problem Midterm Math Review Sheet #9 (w/ proper sig figs)
30 g CH4
1.32 x 1024 molecules H2O
1.99 mol N
1.20 x 1024 atoms Ne
6 mol SO3
4110 g U
QUESTION 12
How many formula units are in 22.3 grams of
magnesium hydroxide?
Answers to problem Midterm Math Review Sheet #9 (w/ proper sig figs)
30 g CH4
1.20 x 1024 atoms Ne
1.32 x 1024 molecules H2O
6 mol SO3
1.99 mol N
4110 g U
QUESTION 13
According to this equation:
2Na3PO4 + 3BaCl2  Ba3(PO4)2 + 6NaCl
How many moles of barium chloride are necessary to
produce 1.25 moles of barium phosphate?
Answers to problem Midterm Math Review Sheet #10 (w/ proper sig figs)
5.0 mol C & 2.5 mol O2
QUESTION 14
Lithium nitride reacts with water to form ammonia and
aqueous lithium hydroxide.
Li3N + 3H2O  NH3 + 3LiOH
What mass of water is needed to react with 32.9 g Li3N?
Answers to problem Midterm Math Review Sheet #10 (w/ proper sig figs)
0.277 g H2 & 9.72 g Cl2
QUESTION 15
Calculate the molarity of a solution containing 400 g CuSO4
in 4.00 L of solution?
Answers to problem Midterm Math Review Sheet #11 (w/ proper sig figs)
0.5 M
0.1 M
56 g
25.5 g
QUESTION 16
A technician experimentally determined the boiling point of
octane to be 124.1C. The actual boiling point of octane is
125.7C. Calculate the percent error.
Answers to problem Midterm Math Review Sheet #12 (w/ proper sig figs)
70.% yield
30.% error
QUESTION 1