Moles, Molecules, and Grams Worksheet – Answer Key
1)
How many molecules are there in 24 grams of FeF3? 1.28 x 1023
molecules
2)
How many molecules are there in 450 grams of Na2SO4? 1.91 x 1024
molecules
3)
How many grams are there in 2.3 x 1024 atoms of silver? 421 grams
4)
How many grams are there in 7.4 x 1023 molecules of AgNO3? 209
grams
5)
How many grams are there in 7.5 x 1023 molecules of H2SO4? 122 grams
6)
How many molecules are there in 122 grams of Cu(NO3)2? 3.92 x 1023
molecules
7)
How many grams are there in 9.4 x 1025 molecules of H2? 312 grams
8)
How many molecules are there in 230 grams of CoCl2? 1.07 x 1024
molecules
9)
How many molecules are there in 2.3 grams of NH4SO2? 1.69 x 1022
molecules
10)
How many grams are there in 3.3 x 1023 molecules of N2I6? 430 grams
11)
How many molecules are there in 200 grams of CCl4? 7.82 x 1023
molecules
12)
How many grams are there in 1 x 1024 molecules of BCl3? 195 grams
13)
How many grams are there in 4.5 x 1022 molecules of Ba(NO2)2? 17.1
grams
14)
How many molecules are there in 9.34 grams of LiCl? 1.33 x 1023
molecules
15)
How many grams do 4.3 x 1021 molecules of UF6 weigh? 2.51 grams
16)
How many molecules are there in 230 grams of NH4OH? 3.96 x 1024
molecules
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Molar Mass Worksheet – Answer Key
Calculate the molar masses of the following chemicals:
1)
Cl2 71 g/mol
2)
KOH 56.1 g/mol
3)
BeCl2 80 g/mol
4)
FeCl3 162.3 g/mol
5)
BF3 67.8 g/mol
6)
CCl2F2 121 g/mol
7)
Mg(OH)2 58.3 g/mol
8)
UF6 352 g/mol
9)
SO2 64.1 g/mol
10)
H3PO4 98 g/mol
11)
(NH4)2SO4 132.1 g/mol
12)
CH3COOH 60 g/mol
13)
Pb(NO3)2 331.2 g/mol
14)
Ga2(SO3)3 379.7 g/mol
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Worksheet – Mole Conversions
Name:
I.
Practice Problems
A. What is the mass of 1 mole (molar mass) of: Answers in g/mole
1. H2 2.016
2. Mg(OH)2 58.319
3. CO2 44.009
4. NH4Cl 53.492
5. CuSO4 159.608
6. AgNO3
169.874
B. Convert from grams to moles, or moles to grams
1. How many moles is 12.5 g of magnesium hydroxide?
.214 moles
2. How many moles is 1.46 g of hydrogen gas (H2)?
.724 moles
3. How many grams are in 4.3 moles of ammonium chloride?
230 grams
C. Convert from moles to molecules, or molecules to moles
1. How many molecules are in 2.0 moles of hydrogen gas (H2)?
1.2044 x 24 molecules
2. How many moles is 2.0 x 1025 molecules of silver nitrate?
33.2 moles
D. How many atoms of oxygen are in 2.4 x 1023 molecules of copper(II) sulfate?
9.6 x1023 atoms of oxygen
II.
Application Problems
A. How many molecules are in 96 g of carbon dioxide?
1.31x1024 molecules
B. How many oxygen atoms are in 96 g of CO2?
2.627 x1024 atoms
C. How many grams would 1.0 x 1025 molecules of copper(II) sulfate weigh?
2650 grams
D. How much does each individual molecule of copper(II) sulfate weigh?
159.608 amu’s
Mole Calculation Worksheet – Answer Key
1)
How many moles are in 15 grams of lithium? 0.46 moles
2)
How many grams are in 2.4 moles of sulfur? 77.0 grams
3)
How many moles are in 22 grams of argon? 0.55 moles
4)
How many grams are in 88.1 moles of magnesium? 2141 grams
5)
How many moles are in 2.3 grams of phosphorus? 0.074 moles
6)
How many grams are in 11.9 moles of chromium? 618.8 grams
7)
How many moles are in 9.8 grams of calcium? 0.24 moles
8)
How many grams are in 238 moles of arsenic? 17,826 grams
What are the molecular weights of the following compounds?
9)
NaOH
40.1 grams
10)
H2O
11)
MgCl2
15)
How many grams are in 4.5 moles of sodium fluoride, NaF? 189 grams
16)
How many moles are in 98.3 grams of aluminum hydroxide, Al(OH)3?
1.26 moles
17)
How many grams are in 0.02 moles of beryllium iodide, BeI2? 5.2 grams
18)
How many moles are in 68 grams of copper (II) hydroxide, Cu(OH)2?
0.70 moles
19)
How many grams are in 3.3 moles of potassium sulfide, K2S? 364.0 grams
20)
How many moles are in 1.2 x 103 grams of ammonia, NH3? 70.6 moles
21)
How many grams are in 2.3 x 10-4 moles of calcium phosphate, Ca3(PO3)2?
0.064 grams
22)
How many moles are in 3.4 x 10-7 grams of silicon dioxide, SiO2?
5.66 x 10-9 moles
23)
How many grams are in 1.11 moles of manganese sulfate, Mn3(SO4)7?
929.5 grams
18.0 grams
95.3 grams
12)
H3PO4
98.0 grams
13)
Mn2Se7
663.0 grams
14)
(NH4)2SO4
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132.1 grams
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Grams/Moles Calculations – Answer Key
Given the following, find the number of moles:
1)
30 grams of H3PO4 0.31 moles
2)
25 grams of HF 1.25 moles
3)
110 grams of NaHCO3 1.31 moles
4)
1.1 grams of FeCl3 0.0068 moles
5)
987 grams of Ra(OH)2 3.80 moles
6)
564 grams of copper 0.11 moles
7)
12.3 grams of CO2 0.28 moles
8)
89 grams of Pb(CH3COO)4 0.20 moles
Given the following, find the number of grams:
9)
4 moles of Cu(CN)2 462 grams
10)
5.6 moles of C6H6 436.8 grams
11)
21.3 moles of BaCO3 4202.5 grams
12)
1.2 moles of (NH4)3PO3 159.6 grams
13)
9.3 x 10-3 moles of SmO 1.5 grams
14)
6.6 moles of ZnO 537.2 grams
15)
5.4 moles of K2SO4 941.2 grams
16)
88.4 moles of NI3 34679.3 grams
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Mass and Moles Worksheet - Answers
1.
How many moles in 34.2 g of sulfur? 1.07 mol S
2.
How many grams in 1.20 moles of carbon? 14.4g C
3.
How many atoms in 3.91 moles of sodium? 2.35 x 1024 atoms Na
4.
How many atoms in 45.22 moles of strontium? 2.72 x 1025 atoms Sr
5.
How many molecules in 31 g of chlorine gas? 2.6 x 1023 molecules Cl2
6.
How many nitrogen atoms in 3.4 moles of ammonia? 2.0 x 1024 atoms N
7.
What mass would 4.52 x 1024 molecules of water have? 135g H2O
8.
How many oxygen atoms in 2.3 x 10-8 g of oxygen? 8.7 x 1014 atoms O
9.
How may atoms in 1.00 ounce of pure gold? 8.65 x 1022 atoms Au
10.
How many sugar molecules (C12H22O11) could you make from 1.0 pound of
carbon? 1.9 x 10 24 molecules C12H22O11
11.
What is the mass of 4.00 moles of sugar? 1370g sugar
12.
How many moles of sulfate ions would be released if 2.5 moles of aluminum
sulfate were dissolved in water? 7.5 mol SO42-
13.
What is the mass of 1.2 x 10-3 moles of sodium chloride? 0.070g NaCl
14.
How many formula units of NaCl are there in 3.55 x 10-6g of salt?
3.65 x 1016 formula units NaCl
15.
How many Volkswagons are there in 2 moles of Volkswagons? 1 x 1024 VW’s
Percentage Composition Worksheet
Give the % composition of all elements in these compounds. Show all work!
________________________________________________________________
1)
ammonium sulfite (NH4)2SO3
% N ______
% H ______
% S ______
% O ______
________________________________________________________________
2)
aluminum acetate Al(C2H3O2)3
% Al ______
% C ______
% H ______
% O ______
________________________________________________________________
3)
sodium bromide
NaBr
% Na ______
% Br ______
________________________________________________________________
4)
copper (II) hydroxide Cu(OH)2
% Cu ______
% O ______
% H ______
________________________________________________________________
5)
magnesium carbonate MgCO3
% Mg ______
% C ______
% O ______
________________________________________________________________
6)
iron (II) phosphate Fe3(PO4)2
% Fe ______
% P ______
% O ______
________________________________________________________________
7)
beryllium nitride
Be3N2
% Be ______
% N ______
________________________________________________________________
8)
potassium cyanide KCN
% K ______
% C ______
% N ______
________________________________________________________________
9)
manganese (III) nitrate Mn(NO3)3
% Mn ______
% N ______
% O ______
________________________________________________________________
10)
lithium phosphide Li3P
% Li ______
% P ______
________________________________________________________________
11)
nickel (III) sulfate
Ni2(SO4)3
% Ni ______
% S ______
% O ______
________________________________________________________________