Unit 1
Section 8
!Optional Reading: Section 3.1 (pgs. 61-61) in the Chemistry: Principles and Reactions textbook
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Mole Conversions
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1 mole of substance = 6.02 x 10 particles of substance = molar mass of substance
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23
The above expression can be broken down into two conversion factors, which can then be used
to convert grams, moles and particles - these conversion factors can also be flipped
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Molar Mass
1 mole
6.02 x 1023 (atoms/ions/formula units)
1 mole
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Examples: Complete the following conversions:
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a. Amount of grams in 0.0654 mol ZnI2
Molar mass of ZnI2
0.0654 𝑚𝑜𝑙 𝑥 319.18 𝑔
= 20.9 𝑔
1 𝑚𝑜𝑙
319.18 𝑔
0.0654 𝑚𝑜𝑙 𝑥 = 20.9 𝑔
1 𝑚𝑜𝑙 1 𝑚𝑜𝑙
b. Amount of moles in 45.6 g PbCrO
4
45.6 𝑔 𝑥 = 0.141 𝑚𝑜𝑙
319.18 𝑔
323.20 𝑔
0.0654 𝑚𝑜𝑙 𝑥 = 20.9 𝑔
1 𝑚𝑜𝑙
1 𝑚𝑜𝑙
45.6 𝑔 𝑥 = 0.141 𝑚𝑜𝑙
323.20 𝑔
1 𝑚𝑜𝑙
6.02 𝑥 10 𝑓𝑜𝑟𝑚𝑢𝑙𝑎 𝑢𝑛𝑖𝑡𝑠
3.46 𝑔 𝑥 𝑥 = 5.31 𝑥 10 𝑓𝑜𝑟𝑚𝑢𝑙𝑎 𝑢𝑛𝑖𝑡𝑠
392.18 𝑔
1 𝑚𝑜𝑙
Molar mass of
PbCrO4
1 𝑚𝑜𝑙
1 𝑚𝑜𝑙45.6 𝑔 𝑥 6.02 𝑥 10 𝑓𝑜𝑟𝑚𝑢𝑙𝑎 𝑢𝑛𝑖𝑡𝑠
= 0.141 𝑚𝑜𝑙
3.46 𝑔 𝑥 𝑥 = 5.31 𝑥 10 𝑓𝑜𝑟𝑚𝑢𝑙𝑎 𝑢𝑛𝑖𝑡𝑠
323.20 𝑔
392.18 𝑔
1 𝑚𝑜𝑙
𝑎𝑡𝑜𝑚𝑠
c. Number of formula1 𝑚𝑜𝑙 𝑁𝐻
units in 3.463 𝑚𝑜𝑙 𝐻
g Cr2(SO4)6.02 𝑥 10
3
3.24 𝑔 𝑥 𝑥 𝑥 = 3.43 𝑥 10 𝑎𝑡𝑜𝑚𝑠
17.04 𝑔
1 𝑚𝑜𝑙 𝑁𝐻
1 𝑚𝑜𝑙 𝐻
1 𝑚𝑜𝑙 𝑁𝐻
3 𝑚𝑜𝑙 𝐻
6.02 𝑥 10 𝑎𝑡𝑜𝑚𝑠
3.24 𝑔 𝑥 6.02 𝑥 10
𝑥 𝑥 = 3.43 𝑥 10 𝑎𝑡𝑜𝑚𝑠
1 𝑚𝑜𝑙
𝑓𝑜𝑟𝑚𝑢𝑙𝑎 𝑢𝑛𝑖𝑡𝑠
17.04 𝑔 (𝑃𝑂
1 𝑚𝑜𝑙 𝑁𝐻
1 𝑚𝑜𝑙 𝐻
3.46 𝑔 𝑥 𝑥 1 𝑚𝑜𝑙 𝐶𝑎
=
5.31 𝑥 10
𝑓𝑜𝑟𝑚𝑢𝑙𝑎 𝑢𝑛𝑖𝑡𝑠
)
3 𝑚𝑜𝑙 𝐶𝑎
40.08 𝑔
4.71 𝑔 𝑥 𝑥 𝑥 = 1.83 𝑔
392.18 𝑔
1 𝑚𝑜𝑙
310.18 𝑔
1 𝑚𝑜𝑙 𝐶𝑎 (𝑃𝑂 )
1 𝑚𝑜𝑙 𝐶𝑎
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4.71 𝑔 𝑥 3.24 𝑔 𝑥 1 𝑚𝑜𝑙 𝐶𝑎 (𝑃𝑂 )
3 𝑚𝑜𝑙 𝐶𝑎
40.08 𝑔
𝑥 𝑥 = 1.83 𝑔
310.18 𝑔
1 𝑚𝑜𝑙 𝐶𝑎 (𝑃𝑂 )
1 𝑚𝑜𝑙 𝐶𝑎
1 𝑚𝑜𝑙 𝑁𝐻
3 𝑚𝑜𝑙 𝐻
6.02 𝑥 10 𝑎𝑡𝑜𝑚𝑠
𝑥 𝑥 = 3.43 𝑥 10 𝑎𝑡𝑜𝑚𝑠
17.04 𝑔
1 𝑚𝑜𝑙 𝑁𝐻
1 𝑚𝑜𝑙 𝐻
1 𝑚𝑜𝑙 𝐶𝑎 (𝑃𝑂 )
3 𝑚𝑜𝑙 𝐶𝑎
40.08 𝑔
3.46 𝑔 𝑥 1 𝑚𝑜𝑙
𝑥 392.18 𝑔
1 𝑚𝑜𝑙
= 0.141 𝑚𝑜𝑙
6.02 𝑥 10 323.20 𝑔
𝑓𝑜𝑟𝑚𝑢𝑙𝑎 𝑢𝑛𝑖𝑡𝑠
45.6 𝑔 𝑥 1 𝑚𝑜𝑙
= 5.31 𝑥 10 𝑓𝑜𝑟𝑚𝑢𝑙𝑎 𝑢𝑛𝑖𝑡𝑠
d. Number of hydrogen atoms in 3.24 g of NH3
1 𝑚𝑜𝑙
6.02 𝑥 10 𝑓𝑜𝑟𝑚𝑢𝑙𝑎 𝑢𝑛𝑖𝑡𝑠
1 𝑚𝑜𝑙 𝑁𝐻
3 𝑚𝑜𝑙 𝐻
6.02 𝑥 10 𝑎𝑡𝑜𝑚𝑠
𝑥 = 5.31 𝑥 10 𝑓𝑜𝑟𝑚𝑢𝑙𝑎 𝑢𝑛𝑖𝑡𝑠
3.24 𝑔 𝑥 𝑥 𝑥 = 3.43 𝑥 10 𝑎𝑡𝑜𝑚𝑠
392.18 𝑔
1 𝑚𝑜𝑙
17.04 𝑔
1 𝑚𝑜𝑙 𝑁𝐻
1 𝑚𝑜𝑙 𝐻
3.46 𝑔 𝑥 Subscripts represent the number of atoms of
a particular element and/or the number of
1 𝑚𝑜𝑙 𝐶𝑎 (𝑃𝑂
3 𝑚𝑜𝑙 𝐶𝑎
moles)of that element
in a formula 40.08 𝑔
1 𝑚𝑜𝑙 𝑁𝐻
3 𝑚𝑜𝑙 𝐻𝑥 6.02 𝑥 10 𝑎𝑡𝑜𝑚𝑠
𝑥 = 1.83 𝑔
3.24 𝑔 𝑥 4.71 𝑔 𝑥 𝑥 𝑥 = 3.43 𝑥 10
𝑎𝑡𝑜𝑚𝑠
310.18 𝑔
1 𝑚𝑜𝑙 𝐶𝑎 (𝑃𝑂 )
1 𝑚𝑜𝑙 𝐶𝑎
17.04 𝑔
1 𝑚𝑜𝑙 𝑁𝐻
1 𝑚𝑜𝑙 𝐻
e. Amount of grams of Ca in 4.71 g of Ca3(PO4)2
4.71 𝑔 𝑥 1 𝑚𝑜𝑙 𝐶𝑎 (𝑃𝑂 )
3 𝑚𝑜𝑙 𝐶𝑎
40.08 𝑔
𝑥 𝑥 = 1.83 𝑔
310.18 𝑔
1 𝑚𝑜𝑙 𝐶𝑎 (𝑃𝑂 )
1 𝑚𝑜𝑙 𝐶𝑎
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Problems for Submission
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1. Problem 1: How many carbon atoms are contained in 2.8 g of C2H4?
2. Problem 2: How many grams of nitrogen are in 25 g of (NH4)2SO4?
3. Problem 3: Determine the number of particles in each of the following:
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a. 62 g NH3
b. 14.9 g N2O5
c. 3.31 g NaClO4
4. Problem 4: Find the mass for the following mole amounts:
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a. 38 mol Na2SO3
b. 5.8 mol CO2
c. 48.1 mol K2CrO4
5. Problem 5: Find the amount of moles of substance in the following:
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a. 26.2 g Li2CO3
b. 41.4 g N2H4
c. 227 g Al2(SO4)3
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