Moles 1.Stoichiometry - “measuring matter” –Water contamination –Radon Levels –Hormone...
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Transcript of Moles 1.Stoichiometry - “measuring matter” –Water contamination –Radon Levels –Hormone...
Moles
1. Stoichiometry - “measuring matter”– Water contamination
– Radon Levels
– Hormone levels in milk
– Impurities in computer chips
Stoichiometry
Moles
H vs HeHe vs CC vs Mg
Atomic Mass
Moles
Mole- Standard Number of atoms or molecules used by chemists
1 mole = 6.022 X 1023 atoms/molecule
Amadeo Avagadro’s Number
Moles
Moles
MolesStoichiometry
Grams Moles Atoms
1 g H 1 mole H 6.02 X 1023 atms
2 g H
12 g C
3 mol C
36.12 X1023 atm He
Grams Moles Atoms
14 g N
42 g N
48 g C
2 mol Na
3 mol Be
36.12 X1023 atm O
30.10 X1023 atm Ca
12.04 X1023 atm Si
MolesStoichiometry
Rounding – 1 decimal place
Iron55.845 g/mole 55.8 g/mol
Sulfur 32.066 g/mole 32.1 g/mol
Oxygen 15.9994 g/mole 16.0 g/mol
Moles
Grams
Moles
Atoms
1. How many Na atoms are present in 11.5 g of Na? (Ans: 3.01 X 1023 atoms)
2. How many C atoms are present in 18.0 g? (Ans: 9.03 X 1023 C)
GMA
Moles
3. What is the mass of 1.20 X 1024 atoms of Na? (Ans: 45.8 grams)
4. What is the mass of 1.51 X 1023 atoms of Be?(Ans: 2.26 g)
5. Start with 0.854 mole V
6. Start with 0.0570 mole Rn
GMA
Moles
How many grams and atoms are in 0.333 moles of Sulfur?
Moles
1. Molar Mass = mass of one mole
2. Units – grams/mole or amu (atomic mass units)
3. What is the molar mass of:1. C
2. O2
3. BaCl2
Molar Mass
MolesMolar Mass
4. What is the molar mass of Cu(NO3)2? (187.5 g/mol)
5. What is the molar mass of Al2(SO4)3? (342.3 g/mol)
Warm-Up
Find everything else if given:
a)0.589 g Ne
b)4.567 X 1024 atoms of K
c)0.00845 mol of Ba
Calculate the molar mass of:
a)KrF4
b)Al(NO3)3
c)Calcium hydroxide
Warm-Up
Find everything else if given:
a)0.589 g Ne (0.0292 mol, 1.76 X1022 atoms)
b)4.567 X 1024 atoms of K (7.58 mol, 297 g)
c)0.00845 mol of Ba (1.16 g, 5.09 X1021 atoms)
Calculate the molar mass of:
a)KrF4 (159.8 g/mol)
b)Al(NO3)3 (213.0 g/mol)
c)Calcium hydroxide (74.1 g/mol)
Moles
1. Monoatomic Elements (C, Fe, Au)GMA
2. Molecules and Ionics (H2O, CaCl2, O2)GMMA
3. You may see “Formula Units” instead of “Molecules” for Ionic compounds
GMMA
Moles
Moles
Grams Moles Molecules Atoms
1 mole of Na
2 mole of Na
1 mole of H2O
1 mole of CH4
3 mole of CH4
GMMA
Moles
1. How many calcium and chlorine atoms are in 200.0 grams of Calcium Chloride?
2. How many hydrogen and oxygen atoms are in 3.60 grams of H2O? (Ans: 2.41 X 1023 atoms H)
GMMA
Moles
3. Given 0.345 mol of Al2(CO3)3, find everything else.
4. Given 3.01X1024 molecules of SO3, find everything else.
5. Given 9.42 X10 22 molecules of C2H4, find everything else.
GMMA
Moles
6. What is the mass of 3.01 X 1022 molecules of Iron(III)Bromide? (Ans: 14.8 g)
GMMA
Moles
1. Given 0.810 g of Mg, find moles and atoms. (0.0333 mol, 2.01X1022 atoms)
2. Given 3.47 X 1022 atoms of fluorine, find grams and moles. (1.10 g. 0.0576 mol)
3. How many carbon atoms are in 36.0 grams of C2H6? (Ans:1.45 X 1024 atoms of C)
4. How many carbon atoms would be needed to weigh the same as one Titanium atom?
Moles
1. How many carbon atoms are in 36.0 grams of carbon? (1.81 X 1024)
2. How many carbon atoms are in 36.0 grams of C2H6? (Ans:1.45 X 1024 atoms of C)
Mixed Examples
Moles
Warm-Up Problems (find everything else)
a) 10.0 g C
b) 10.0 g C2H6
c) 4.00 X 1023 atoms of S
d) 4.00 X 1023 molecules of SO2
e) 0.440 moles of SO2
Mixed Examples
Mixed Examples
Grams Moles Molecules Atoms
10.0 g C 0.833 ======== 5.02 X 1023
10.0 g C2H6 0.333 2.01 X 1023 4.02 X 1023 C
12.1 X 1023 H
21.3 g S 0.664 ======== 4X1023 S
42.6 g SO2 0.664 4X1023 SO24 X 1023 S
8 X 1023 O
28.2 g SO2 0.44 SO2 2.65 X 1023 2.65 X 1023 S
5.30 X 1023 O
164.1 g/mol 197.0 g/mol 234.0 g/mol71.0 g/mol 106.8 g/mol
Moles
1. Definition - % of the elements in a compound by mass
2. Class Example
Girls 12
Boys 13
Percent Composition
Moles
1. What is the % composition of CaCl2? (Ans: 36.1 %, 63.9%)
2. What is the % composition of C2H5OH? (Ans: 52.2 %, 13.0 %, 34.8 %)
3. What is the % composition of Al2(SO4)3? (Ans: 15.8 %, 28.1 %, 56.1 %)
Percent Composition
Moles
1. Definition – The simplest ratio of the elements in a compound
2. Class with6 girls, 9 boys
Empirical Formula
Moles
3. Examples
Formula Empirical Form.
C2H2
Al4S6
C6H12O6
C12H24O12
Empirical Formula
Moles
1. What is the EF of a compound that has 0.900 g Ca and 1.60 g Cl?
Rules
- Go to moles
- Divide by the smaller
Empirical Formula
Moles
2. What is the EF of a compound that is 40.0 % C, 6.67 % H and 53.3 % O?
3. What is the EF of a compound that is 66.0 % Ca and 34.0% P?
4. What is the EF of a compound that is 43.7 % P and 56.3 % O?
Empirical Formula
a. Write the formula of calcium nitrate.b. Calculate the percent composition of
calcium nitrate. (24.4% Ca, 17.1% N, 58.5% O)
c. A compound was analyzed and found to contain 13.5 g Ca, 10.8 g O, and 0.675 g H. Calculate the empirical formula of the compound? (CaO2H2 or Ca(OH)2)
d. A compound is 69.6% manganese, the rest is oxygen. Calculate the empirical formula.
Moles
1. Empirical – Only tells you the ratios of the elements
2. Molecular – Tells you the true number of each element
Molecular Formula
Moles
EF MF
CH2O CH2O (30 g/mol)
C2H4O2 (60 g/mol)
C3H6O3 (90 g/mol)
C4H8O4 (120 g/mol)
Molecular Formula
Moles
1. What is the MF of benzene if it has an EF of CH and a molar mass of 78.0 g/mol?
2. What is the MF of a compound if it has an EF of AgCO2 and a molar mass of 304.0 g/mol?
Molecular Formula
Moles
3. What is the MF of a compound that is 40.9% C, 4.58 % H and 54.5 % O? It has a molar mass between 350 and 360 g/mol.
4. What is the MF of a compound that contains 4.90 grams of N and 11.2 g of O? The molar mass is about 90 g/mol.
Molecular Formula
Moles1. 33.9% Cu, 14.9% N, 51.2% O
2. 57.5% Na, 40.0% O, 2.5% H
3. 36.1% Ca, 63.9% Cl
4. 70% Fe, 30% O
5. 32% Fe, 27.6% C, 3.5% H, 36.8% O
6. 37.4% Cu, 62.6% Cl
7. 80.2% Ba, 18.7% O, 1.2% H
8. 25.9% N, 74.1% O
9. 60% Ti, 40% O
10.39.8% Cu, 20.1% S, 40.0% O
CaO KMnO4
NH3 N2H4O3
AlI3 H2SO4
KI NaNO3
SO2 H3PO4
K2Cr2O7 C8H8O3
N2H8SO4 As2O3
AgNO3
C2H2O4
C8H16O4
C2H6
C2H4Cl2
C6H4Cl2
N2O4
Moles15 grams mol atoms
a) 0.390 0.017 1 X 1022
b) 1.57 X 106 3.01 X 104 1.81 X 1028
c) 43.2 (Boron) 4.00 2.41 X 1024
d) 4.25 X 10-61.09 X 10-76.55 X 1016
e) 0.123 6.08 X 10-33.66 X 1021
17 a) 41.0 g b) 400. g c) 3.67X106g
19 a) 10.0 mol b) 122 mol c) 3.16X10-
23mol
26. a) 267.6 g/mol b) 119.0 g/mol c) 318.0 g/mol
d) 103.8 g/mol e) 220.0 g/mol
Moles30 Grams Moles Molecules
a) 176 3.67 2.21 X 1024
b) 0.173 3.75 X 10-32.26 X 1021
c) 3.0 X 10-20 2.5 X 10-22 150
d) 49.7 0.141 8.50 X 1022
32.46.7 g/mol
46 a) 3.2%, 19.4%, 77.4%
b) 38.8%, 61.2%
c) 12.7%, 19.7%, 67.6%
d) 12.2%, 5.2%, 27.0%, 56.6%
Moles48 63.6%, 6.0%, 21.2%, 9.3%
57. a) SiO2 b) C2S c) X5Y6 d) Fe2C3O9
59.K2S2O3
61.NH3C3
64.Na2CrO4
67.C3N3O9H5
69. N4S4
72.C6H12O6
88.K2C2O6
Moles Calculate the empirical formula of a compound that contains 55.3 grams of potassium, 14.6 g of phosphorus, and 30.1 g of oxygen.
Moles1. Make up a compound containing 3 elements1. No subscripts >5
2. Use both even and odd numbers
3. Ex: C3O5F2
2. Calculate the percent composition of your imaginary compound. Also calculate the molar mass. Write these numbers down on an index card.
3. Give your card to another group. See if they can determine the formula of your compound.
Moles
Beware the
Mole Man