ADVANCED HONORS CHEMISTRY - CHAPTER 10
NAME:
CHEMICAL QUANTITIES
DATE:
MOLAR MASS CALCS WKST - ANSWERS - V6
PAGE:
Directions: Write the correct formula for the following chemical compounds and determine the molar
mass for each compound to three significant figures. To receive credit for this assignment, you must
show all work on a separate piece of paper. Circle your answer. Note that the units for all answers may
be in atomic mass units (amu) per atom, ion, molecule, or formula unit. Likewise, the units for all
answers may also be in grams (g) per mole of atoms, ions, molecules, or formula units. Kudos to Mrs.
Doyle for creating this worksheet.
Chemical Name
Chemical Formula
Calculations
⎛
⎞
gK
(1 mol K ) ⎜⎝ 39.1
mol K ⎟⎠
= 39.1 g K
⎛ 54.9 g Mn ⎞
+ 1 mol Mn ⎜
= 54.9 g Mn
⎝ mol Mn ⎟⎠
(
1. potassium permanganate
KMnO4
)
⎛ 16.0 g O ⎞
+ 4 mol O ⎜
= 64.0 g O
⎝ mol O ⎟⎠
(
)
Total Mass = 158.0 g
Final Mass = 158 g
⎛
⎞
g Mg
( 3 mol Mg ) ⎜⎝ 24.3
mol Mg ⎟⎠
2. magnesium nitride
= 72.9 g Mg
⎛ 14.0 g N ⎞
+ 2 mol N ⎜
= 28.0 g N
⎝ mol N ⎟⎠
(
Mg3N2
)
Total Mass = 100.9 g
Final Mass = 101 g
1
Chemical Name
Chemical Formula
Calculations
⎛
⎞
g Al
( 2 mol Al ) ⎜⎝ 27.0
mol Al ⎟⎠
= 54.0 g Al
⎛ 32.1 g S ⎞
+ 3 mol S ⎜
= 96.3 g S
⎝ mol S ⎟⎠
(
3. aluminum sulfate
Al2(SO4)3
)
⎛ 16.0 g O ⎞
+ 12 mol O ⎜
= 192 g O
⎝ mol O ⎟⎠
(
)
Total Mass = 342.3 g
Final Mass = 342 g
⎛
⎞
gN
( 3 mol N ) ⎜⎝ 14.0
mol N ⎟⎠
= 42.0 g N
⎛ 1.01 g H ⎞
+ 12 mol H ⎜
= 12.1 g H
⎝ mol H ⎟⎠
(
4. ammonium phosphate
(NH4)3PO4
)
⎛ 31.0 g P ⎞
+ 1 mol P ⎜
= 31.0 g P
⎝ mol P ⎟⎠
(
)
⎛ 16.0 g O ⎞
+ 4 mol O ⎜
= 64.0 g O
⎝ mol O ⎟⎠
(
)
Total Mass = 149.1 g
Final Mass = 149 g
2 - AHC - Chapter 10 - Molar Mass Calculations - Answers - V6
Chemical Name
Chemical Formula
Calculations
⎛
⎞
g Zn
(1 mol Zn ) ⎜⎝ 65.4
mol Zn ⎟⎠
= 65.4 g Zn
⎛ 12.0 g C ⎞
+ 4 mol C ⎜
= 48.0 g C
⎝ mol C ⎟⎠
(
)
⎛ 1.01 g H ⎞
+ 6 mol H ⎜
= 6.06 g H
⎝ mol H ⎟⎠
(
5. zinc acetate dihydrate
Zn(C2H3O2)2 · 2Η2Ο
)
⎛ 16.0 g O ⎞
+ 4 mol O ⎜
= 64.0 g O
⎝ mol O ⎟⎠
(
)
⎛ 1.01 g H ⎞
+ 4 mol H ⎜
= 4.04 g H
⎝ mol H ⎟⎠
(
)
⎛ 16.0 g O ⎞
+ 2 mol O ⎜
= 32.0 g O
⎝ mol O ⎟⎠
(
)
Total Mass = 219.5 g
Final Mass = 220. g
⎛
⎞
g Ba
(1 mol Ba ) ⎜⎝ 137
mol Ba ⎟⎠
= 137 g Ba
⎛ 35.5 g Cl ⎞
+ 2 mol Cl ⎜
= 71.0 g Cl
⎝ mol Cl ⎟⎠
(
6. barium chlorate
Ba(ClO3)2
)
⎛ 16.0 g O ⎞
+ 6 mol O ⎜
= 96.0 g O
⎝ mol O ⎟⎠
(
)
Total Mass = 304.0 g
Final Mass = 304 g
3 - AHC - Chapter 10 - Molar Mass Calculations - Answers - V6
Chemical Name
Chemical Formula
Calculations
(2
⎛ 1.01 g H ⎞
mol H ⎜
= 2.02 g H
⎝ mol H ⎟⎠
)
⎛ 12.0 g C ⎞
+ 1 mol C ⎜
= 12.0 g C
⎝ mol C ⎟⎠
(
7. carbonic acid
H2CO3
)
⎛ 16.0 g O ⎞
+ 3 mol O ⎜
= 48.0 g O
⎝ mol O ⎟⎠
(
)
Total Mass = 62.02 g
Final Mass = 62.0 g
(2
8. hydrosulfuric acid
H2 S
⎛ 1.01 g H ⎞
mol H ⎜
= 2.02 g H
⎝ mol H ⎟⎠
)
⎛ 32.1 g S ⎞
+ 1 mol S ⎜
= 32.1 g S
⎝ mol S ⎟⎠
(
)
Total Mass = 34.12 g
Final Mass = 34.1 g
⎛
⎞
g Cu
(1 mol Cu ) ⎜⎝ 63.6
mol Cu ⎟⎠
9. copper (II) oxide
CuO
= 63.6 g Cu
⎛ 16.0 g O ⎞
+ 1 mol O ⎜
= 16.0 g O
⎝ mol O ⎟⎠
(
)
Total Mass = 79.6 g
Final Mass = 79.6 g
4 - AHC - Chapter 10 - Molar Mass Calculations - Answers - V6
Chemical Name
Chemical Formula
Calculations
⎛
⎞
g Ca
(1 mol Ca ) ⎜⎝ 40.1
mol Ca ⎟⎠
= 40.1 g Ca
⎛ 16.0 g O ⎞
+ 2 mol O ⎜
= 32.0 g O
⎝ mol O ⎟⎠
(
10. calcium hydroxide
Ca(OH)2
)
⎛ 1.01 g H ⎞
+ 2 mol H ⎜
= 2.02 g H
⎝ mol H ⎟⎠
(
)
Total Mass = 74.12 g
Final Mass = 74.1 g
5 - AHC - Chapter 10 - Molar Mass Calculations - Answers - V6