IIIIIIIV The Mole I. Molar Conversions What is the Mole? A counting number (like a dozen or a pair)...
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Transcript of IIIIIIIV The Mole I. Molar Conversions What is the Mole? A counting number (like a dozen or a pair)...
![Page 1: IIIIIIIV The Mole I. Molar Conversions What is the Mole? A counting number (like a dozen or a pair) Avogadro’s number 6.02 10 23 1 mole = 6.02 10.](https://reader035.fdocuments.us/reader035/viewer/2022062409/56649efd5503460f94c11024/html5/thumbnails/1.jpg)
I II III IV
The Mole
I. Molar Conversions
![Page 2: IIIIIIIV The Mole I. Molar Conversions What is the Mole? A counting number (like a dozen or a pair) Avogadro’s number 6.02 10 23 1 mole = 6.02 10.](https://reader035.fdocuments.us/reader035/viewer/2022062409/56649efd5503460f94c11024/html5/thumbnails/2.jpg)
What is the Mole?
A counting number (like a dozen or a pair)
• Avogadro’s number 6.02 1023
• 1 mole = 6.02 1023 things. (things can be
atoms, molecules, formula units)
A large amount!!!!
![Page 3: IIIIIIIV The Mole I. Molar Conversions What is the Mole? A counting number (like a dozen or a pair) Avogadro’s number 6.02 10 23 1 mole = 6.02 10.](https://reader035.fdocuments.us/reader035/viewer/2022062409/56649efd5503460f94c11024/html5/thumbnails/3.jpg)
1 mole of hockey pucks would equal the mass of the moon!
A. What is the Mole?
1 mole of pennies would cover the Earth 1/4 mile deep!
1 mole of basketballs would fill a bag the size of the earth!
![Page 4: IIIIIIIV The Mole I. Molar Conversions What is the Mole? A counting number (like a dozen or a pair) Avogadro’s number 6.02 10 23 1 mole = 6.02 10.](https://reader035.fdocuments.us/reader035/viewer/2022062409/56649efd5503460f94c11024/html5/thumbnails/4.jpg)
Example
How many molecules are in 2.50 moles of C12H22O11?
2.50 mol6.02 1023
molecules
1 mol= 1.51 1024
molecules C12H22O11
![Page 5: IIIIIIIV The Mole I. Molar Conversions What is the Mole? A counting number (like a dozen or a pair) Avogadro’s number 6.02 10 23 1 mole = 6.02 10.](https://reader035.fdocuments.us/reader035/viewer/2022062409/56649efd5503460f94c11024/html5/thumbnails/5.jpg)
Mole- Volume
At the same temperature: Equal volumes of gases contain
equal numbers of moles STP
Standard temperature and pressure 1 mole of any gas at STP has a
volume of :22.4 L
![Page 6: IIIIIIIV The Mole I. Molar Conversions What is the Mole? A counting number (like a dozen or a pair) Avogadro’s number 6.02 10 23 1 mole = 6.02 10.](https://reader035.fdocuments.us/reader035/viewer/2022062409/56649efd5503460f94c11024/html5/thumbnails/6.jpg)
Example
How many moles of neon are in 44.8L of neon at STP?
44.8 L 1 mol
22.4 L= 2 mol
![Page 7: IIIIIIIV The Mole I. Molar Conversions What is the Mole? A counting number (like a dozen or a pair) Avogadro’s number 6.02 10 23 1 mole = 6.02 10.](https://reader035.fdocuments.us/reader035/viewer/2022062409/56649efd5503460f94c11024/html5/thumbnails/7.jpg)
Molar Mass
How much do I weigh??
![Page 8: IIIIIIIV The Mole I. Molar Conversions What is the Mole? A counting number (like a dozen or a pair) Avogadro’s number 6.02 10 23 1 mole = 6.02 10.](https://reader035.fdocuments.us/reader035/viewer/2022062409/56649efd5503460f94c11024/html5/thumbnails/8.jpg)
Molar Mass
Mass of 1 mole (6.02 X 1023 atoms or molecules) of an
element or compound.
Atomic mass tells the... atomic mass units per atom (amu) grams per mole (g/mol)
Round to 2 decimal places when calculating
![Page 9: IIIIIIIV The Mole I. Molar Conversions What is the Mole? A counting number (like a dozen or a pair) Avogadro’s number 6.02 10 23 1 mole = 6.02 10.](https://reader035.fdocuments.us/reader035/viewer/2022062409/56649efd5503460f94c11024/html5/thumbnails/9.jpg)
Molar Mass ExamplesThis is easy! Just look at the periodic table!• Phosphorus
• Aluminum
• Helium
• Silver
30.97 g/mol
26.98 g/mol
4.00 g/mol
107.87 g/mol
![Page 10: IIIIIIIV The Mole I. Molar Conversions What is the Mole? A counting number (like a dozen or a pair) Avogadro’s number 6.02 10 23 1 mole = 6.02 10.](https://reader035.fdocuments.us/reader035/viewer/2022062409/56649efd5503460f94c11024/html5/thumbnails/10.jpg)
Molar Mass Examples
WATER:
H2O
Ca(OH)2
Ca 40.08 + O2(16) + H 2(1.01) = 74.10 g/mol
H →
O →
= 2.02 g/mol2 x 1.01 g/mol
1 x 16.0 g/mol = 16.0 g/mol
18.02 g/mol
![Page 11: IIIIIIIV The Mole I. Molar Conversions What is the Mole? A counting number (like a dozen or a pair) Avogadro’s number 6.02 10 23 1 mole = 6.02 10.](https://reader035.fdocuments.us/reader035/viewer/2022062409/56649efd5503460f94c11024/html5/thumbnails/11.jpg)
Molar Mass
sodium bicarbonate
sucrose
NaHCO3
84.01 g/mol
C12H22O11
342.34 g/mol
![Page 12: IIIIIIIV The Mole I. Molar Conversions What is the Mole? A counting number (like a dozen or a pair) Avogadro’s number 6.02 10 23 1 mole = 6.02 10.](https://reader035.fdocuments.us/reader035/viewer/2022062409/56649efd5503460f94c11024/html5/thumbnails/12.jpg)
Example
How many moles of carbon are in 26 g of carbon?
26 g C 1 mol C
12.01 g C= 2.2 mol C
![Page 13: IIIIIIIV The Mole I. Molar Conversions What is the Mole? A counting number (like a dozen or a pair) Avogadro’s number 6.02 10 23 1 mole = 6.02 10.](https://reader035.fdocuments.us/reader035/viewer/2022062409/56649efd5503460f94c11024/html5/thumbnails/13.jpg)
Examples
Find the mass of 2.1 1024 molecules of NaHCO3.
2.1 1024
molecules 1 mol
6.02 1023
molecules
= 290 g NaHCO3
84.01 g
1 mol
![Page 14: IIIIIIIV The Mole I. Molar Conversions What is the Mole? A counting number (like a dozen or a pair) Avogadro’s number 6.02 10 23 1 mole = 6.02 10.](https://reader035.fdocuments.us/reader035/viewer/2022062409/56649efd5503460f94c11024/html5/thumbnails/14.jpg)
A. Percentage Composition
the percentage by mass of each element in a compound
100mass total
element of massncompositio %
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100 =
A. Percentage Composition
%Cu =127.10 g Cu
159.17 g Cu2S 100 =
%S =32.07 g S
159.17 g Cu2S
79.852% Cu
20.15% S
Find the % composition of Cu2S.
![Page 16: IIIIIIIV The Mole I. Molar Conversions What is the Mole? A counting number (like a dozen or a pair) Avogadro’s number 6.02 10 23 1 mole = 6.02 10.](https://reader035.fdocuments.us/reader035/viewer/2022062409/56649efd5503460f94c11024/html5/thumbnails/16.jpg)
%Fe =28 g
36 g 100 =78% Fe
%O =8.0 g
36 g 100 =22% O
Find the percentage composition of a sample that is 28 g Fe and 8.0 g O.
A. Percentage Composition
![Page 17: IIIIIIIV The Mole I. Molar Conversions What is the Mole? A counting number (like a dozen or a pair) Avogadro’s number 6.02 10 23 1 mole = 6.02 10.](https://reader035.fdocuments.us/reader035/viewer/2022062409/56649efd5503460f94c11024/html5/thumbnails/17.jpg)
How many grams of copper are in a 38.0-gram sample of Cu2S?
(38.0 g Cu2S)(0.79852) = 30.3 g Cu
Cu2S is 79.852% Cu
A. Percentage Composition
![Page 18: IIIIIIIV The Mole I. Molar Conversions What is the Mole? A counting number (like a dozen or a pair) Avogadro’s number 6.02 10 23 1 mole = 6.02 10.](https://reader035.fdocuments.us/reader035/viewer/2022062409/56649efd5503460f94c11024/html5/thumbnails/18.jpg)
I II III IV
The Mole
Empirical/Molecular Formulas
![Page 19: IIIIIIIV The Mole I. Molar Conversions What is the Mole? A counting number (like a dozen or a pair) Avogadro’s number 6.02 10 23 1 mole = 6.02 10.](https://reader035.fdocuments.us/reader035/viewer/2022062409/56649efd5503460f94c11024/html5/thumbnails/19.jpg)
B. Empirical Formula
C2H6
CH3
reduce subscripts
Smallest whole number ratio of atoms in a compound
![Page 20: IIIIIIIV The Mole I. Molar Conversions What is the Mole? A counting number (like a dozen or a pair) Avogadro’s number 6.02 10 23 1 mole = 6.02 10.](https://reader035.fdocuments.us/reader035/viewer/2022062409/56649efd5503460f94c11024/html5/thumbnails/20.jpg)
Empirical Formula
1. Find mass (or %) of each element. (may be given)
2. Find moles of each element. (g to moles)
3. Divide moles by the smallest # to find subscripts.
4. When necessary, multiply subscripts by 2, 3, or 4 to get whole #’s.
![Page 21: IIIIIIIV The Mole I. Molar Conversions What is the Mole? A counting number (like a dozen or a pair) Avogadro’s number 6.02 10 23 1 mole = 6.02 10.](https://reader035.fdocuments.us/reader035/viewer/2022062409/56649efd5503460f94c11024/html5/thumbnails/21.jpg)
Empirical Formula
Find the empirical formula for a sample of 25.9% N and 74.1% O.
25.9 g 1 mol
14.01 g = 1.85 mol N
74.1 g 1 mol
16.00 g = 4.63 mol O
1.85 mol
1.85 mol
= 1 N
= 2.5 O
![Page 22: IIIIIIIV The Mole I. Molar Conversions What is the Mole? A counting number (like a dozen or a pair) Avogadro’s number 6.02 10 23 1 mole = 6.02 10.](https://reader035.fdocuments.us/reader035/viewer/2022062409/56649efd5503460f94c11024/html5/thumbnails/22.jpg)
Empirical Formula
N1O2.5Need to make the subscripts whole
numbers multiply by 2
N2O5
![Page 23: IIIIIIIV The Mole I. Molar Conversions What is the Mole? A counting number (like a dozen or a pair) Avogadro’s number 6.02 10 23 1 mole = 6.02 10.](https://reader035.fdocuments.us/reader035/viewer/2022062409/56649efd5503460f94c11024/html5/thumbnails/23.jpg)
Examples
An organic compound is found to contain 92.25% carbon and 7.75% hydrogen. Determine the empirical formula.
Empirical Formula: CH What is the empirical formula of a
compound that contains 53.73% Fe and 46.27% S?
Empirical Formula: Fe2S3
![Page 24: IIIIIIIV The Mole I. Molar Conversions What is the Mole? A counting number (like a dozen or a pair) Avogadro’s number 6.02 10 23 1 mole = 6.02 10.](https://reader035.fdocuments.us/reader035/viewer/2022062409/56649efd5503460f94c11024/html5/thumbnails/24.jpg)
Molecular Formula “True Formula” - the actual number
of atoms in a compound
CH3
C2H6
empiricalformula
molecularformula
?
![Page 25: IIIIIIIV The Mole I. Molar Conversions What is the Mole? A counting number (like a dozen or a pair) Avogadro’s number 6.02 10 23 1 mole = 6.02 10.](https://reader035.fdocuments.us/reader035/viewer/2022062409/56649efd5503460f94c11024/html5/thumbnails/25.jpg)
C. Molecular Formula
1. Find the empirical formula.2. Find the empirical formula mass.3. Divide the molecular mass by the
empirical mass. 4. Multiply each subscript by the
answer from step 3.
nmass EF
mass MF nEF
![Page 26: IIIIIIIV The Mole I. Molar Conversions What is the Mole? A counting number (like a dozen or a pair) Avogadro’s number 6.02 10 23 1 mole = 6.02 10.](https://reader035.fdocuments.us/reader035/viewer/2022062409/56649efd5503460f94c11024/html5/thumbnails/26.jpg)
Molecular Formula The empirical formula for ethylene
is CH2. Find the molecular formula if the molecular mass is 28.1 g/mol?
28.1 g/mol
14.03 g/mol = 2.00
empirical mass = 14.03 g/mol
(CH2)2 C2H4