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Moles
Moles
Like a recipe:
Reactants Products
2H2(g) + O2(g) 2H2O(l)
coefficients subscripts
Balancing Eqns
Moles
Symbols Yields or Produces(s) solid(l) liquid (pure liquid)(aq) aqueous (dissolved in water)(g) or gas
Balancing Eqns
Moles
Copper(II) Chloride reacts with Iron(III) Sulfate to form Copper(II)Sulfate and Iron(III) Chloride
Aluminum nitrate reacts with Sodium hydroxide to form Aluminum hydroxide and Sodium nitrate
Balancing
MolesSome Types of Reactions
1. Synthesis
Al + Cl2 AlCl3
CaO(s) + CO2(g) CaCO3(s)
2. Decomposition
HgO(s) Hg(l) + O2(g)
CaCO3(s) CaO(s) + CO2(g)
Moles
3. Combustion
Fe + O2 Fe2O3
C4H10 + O2 CO2 + H2O
4. Other TypesSingle ReplacementDouble Replacement
Some Types of Reactions
MolesKnow your reactions well!!!!
Moles
Mole
1 dozen = 12 items
1 mole = 6.022 X 1023 atoms/molecules
1 gram hydrogen = 6.022 X 1023 atoms of hydrogen
Stoichiometry
Moles
Moles
MolesStoichiometry
Grams Moles Atoms
1 g H 1 mole H 6.02 X 1023 atms
2 g H
12 g C
36 g C
48 g O
MolesStoichiometry
Grams Moles Molecules Atoms
16 g CH4
8 g CH4
88 g CO2
131 g Ba(NO3)2
Moles
1. Molar Mass = mass of one mole
2. Element= atomic mass
1 mole of O = 16.0 grams
3. Molecule or Compound – sum of all the atoms
Molar Mass
Moles
Moles
Calculate the molar mass of
Barium
O2
BaCl2?
Fe2(SO4)3?
Molar Mass
Moles
Grams
Moles
Atoms
1. How many C atoms are present in 18.0 g? (Ans: 9.03 X 1023 C)
2. What is the mass of 1.20 X 1024 atoms of Na? (Ans: 45.8 grams)
GMA
Moles
3. What is the mass of 1.51 X 1023 atoms of Be?(Ans: 2.26 g)
5. How many atoms and grams are in 0.400 mol of Radium? (Ans: 90.4 g, 2.41 X 1023 atoms)
GMA
Moles
1. Monoatomic Elements (C, Fe, Au)GMA
2. Molecules and Ionics (H2O, CaCl2, O2)GMMA
GMMA
Moles
3. Molecules and formula units work the same when convertingMolecules = Molecular CompsFormula Units = Ionic Compounds
GM M
A
GMMA
Moles
1. How many calcium and chlorine atoms are in 200.0 grams of Calcium Chloride?
(Ans: 2.17 X 1024 atoms Cl)
GMMA
Moles
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 3.01X1024 molecules of SO3, find everything else.
4. Given 3.01 X 1022 molecules of Iron(III)bromide, find everything else.
GMMA
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
Homework Problems (find everything else)
a) 10.0 g C
b) 10.0 g C2H6
c) 4.0 X 1023 atoms of S
d) 4.0 X 1023 molecules of SO2
e) 0.44 moles of SO2
Mixed Examples
Moles
1. Empirical formula - simplest ratio of the elements in a compound
2. 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 66.0 % Ca and 34.0% P?
3. What is the EF of a compound that is 43.7 % P and 56.3 % O?
Empirical Formula
Moles
1. Empirical –ratios of the elements2. Molecular –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?
2. 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.
Molecular Formula
Moles
What coefficients mean:
2 Na + Cl2 2NaCl
2 Na 1 Cl2 2NaCl
4 Na
6 Na
Reaction Stoich.
Moles
2 Na + Cl2 2NaCl
4 Cl2
2 moles Na
10 moles Na
ONLY WORKS FOR MOLES AND MOLECULES
Reaction Stoich.
Moles
1. How many moles of H2 and O2 must react to form 6 moles of H2O?
2. How many moles of KCl and O2 are formed from the decomposition of 6 moles of KClO3?
Reaction Stoich.
Moles
3. How many grams of oxygen are needed to react with 14.6 g of Na to form Na2O? (Ans: 5.08 g)
4. How many grams of P4 and O2 are needed to make 3.62 g of P2O5? (Ans: 1.58 g, 2.04 g)
Reaction Stoich.
Moles
5. What mass of oxygen is needed to react with 16.7 g of iron to form Iron(III)oxide? (Ans: 7.18 g)
4Fe + 3O2 2Fe2O3
Reaction Stoich.
Moles
Calculate the mass of sodium bromide and oxygen that are formed from the decomposition of 50.0 grams of sodium bromate (NaBrO3).
(34.1 g NaBr, 15.9 g O2)
Moles
1. Sandwich analogy:
13 slices of bread
4 pieces of turkey
Maximum # of sandwiches?
2. Limiting Reactant – Totally consumed in a reaction. No leftovers
Limiting Reactant
Moles
1. How many grams of H2SO4 can be formed from the rxn of 5.00 moles of SO3 and 2.00 moles of H2O?
SO3 + H2O H2SO4
(Ans: 196 g)
Limiting Reactant
Moles
1. How many grams of H2O can be formed from the rxn of 6.00 moles of H2 and 4.00 moles of O2?
O2 + H2 H2O
Limiting Reactant
Moles
2. How many grams of NaCl can be formed from the reaction of 0.300 mol of Na and 0.100 mol of Cl2?
2Na + Cl2 2NaCl
(Ans: 11.7 g)
Limiting Reactant
Moles
3. How many grams of Ag can be formed from the rxn of 2.00 g of Zn and 2.50 g of silver nitrate? How much excess reactant remains?
Zn + AgNO3 Ag + Zn(NO3)2
(Ans: 1.59 g Ag, 1.52 g xs zinc)
Limiting Reactant
Moles
4. How many grams of Ba3(PO4)2 can be formed from the rxn of 3.50 g of Na3PO4 and 6.40 g of Ba(NO3)2?
Na3PO4 + Ba(NO3)2 Ba3(PO4)2 + NaNO3
(Ans: 4.92 g)
Limiting Reactant
Moles
6. How many grams of Ag2S can be formed from the rxn of 15.6 g of Ag and 2.97 g of H2S? (Assume O2 is in excess)
4Ag + 2H2S + O2 2Ag2S + 2H2O
(Ans: 18.1 g)
Limiting Reactant
Moles
A. Formula:
Actual Yield X 100 = % Yield
Theoretical Yield
Percent Yield
Moles
1. What is the % yield if you start with 10.00 grams of C and obtain 1.49 g of H2 gas?
C + H2O CO + H2
(Ans: 89.4%)
Percent Yield
Moles
2. Carbon was heated strongly in sulfur(S8) to form carbon disulfide. What is the percent yield if you start with 13.51 g of sulfur and collect 12.5 g of CS2?
4C + S8 4CS2
(Ans: 78.0%)
Percent Yield
Moles
3. 36.7 grams of CO2 were formed from the rxn of 40.0 g of CH3OH and 46.0 g of O2. What is the % yield?
2CH3OH + 3O2 2CO2 + 4H2O
(ANS: 87%)
Percent Yield
Moles
MolesIn this experiment, magnesium chloride was prepared and its empirical formula was compared to the accepted formula of MgCl2. To prepare magnesium chloride, 0.40 grams of magnesium powder was combined with 10 mL of 0.10 M HCl. The mixture was allowed to react, and heated to dryness. The mass of the resulting crystals was used to calculate the empirical formula. The average calculated formula of MgCl1.8 had a 10% error and a range was 0.40 chlorine atoms. This procedure was not effective because while it was accurate, it was not precise.
Moles
8a) SO3 + H2O H2SO4
b) B2S3 + 6H2O 2H3BO3 + 3H2S
c) 4PH3 + 8O2 6H2O + P4O10
d) 2Hg(NO3)2 2HgO + 4NO2 + O2
e) Cu + 2H2SO4 CuSO4 + SO2 + 2H2O
Moles
12.a) 6 1 2 14. a) 1 1 1
b) 1 3 2 b) 1 6 2 3
c) 2 2 1 4 c) 1 2 2 1
d) 1 6 3 2 d) 2 2 4 1
e) 3 2 1 6 e) 1 2 1 1 2
f) 2 1 1 2
g) 4 9 4 10 2
Moles18.a) 4Al + 3O2 2Al2O3
b) Cu(OH)2 CuO + H2O
c) C7H16 + 11O2 7CO2 + 8H2O
d) 2C5H12O + 15O2 10CO2 + 12H2O
20. 2 9 6 6
1 1 2
1 6 5 3
1 3 2
1 1 2
22.a) 44.0 g/mol b) 122.0 g/mol
c) 58.3 g/mol d) 60.0 g/mol e) 130.0 amu
Moles24. 26.0 g/mole 92.3% C
176.0 g/mole 4.5% H
132.1 g/mole 6.1% H
300.1 g/mole 65.01% Pt
272.0 g/mole 11.8% O
305.0 g/mole 70.8 % C
Moles
46 a)K3PO4 b) Na2SiF6c) C12H12N2O3
48 a) H2C2O4 b) C4H8O2
50 a) C13H18O2 b) C5H14N2 c) C9H13O3N
Moles
58.a) 0.800 mol CO2 b) 14.7 g C6H12O6
c) 7.16 g CO2
60.a) 0.939 mol Fe2O3 b) 78.9 g CO
c) 105 g Fe d) 229 g= 229 g
Moles48.a) H2C2O4 b) C4H8O2
50. a) C13H8O2 b)C5H14N2
c) C9H13O3N
58.a) 0.800 mol CO2 b) 14.7 g C6H12O6
c) 7.18 g CO2
60.a) Fe2O3 + 3CO 2Fe + 3CO2
b) 78.9 g CO2
c) 124 g CO2
d) 229 g = 229 g
Moles62.a) CaH2 + 2H2O Ca(OH)2 + 2H2
b) 88.75 g CaH2
64. a) 15.6 mol O2 b) 35.0 g O2 c) 9175.1 g
72.0.167 mol Al2(SO4)3 form
0.333 mol Al(OH)3 react
0.167 mol AL(OH)3 remain
74.a) O2 is limiting reactant
b) 1.86 g H2O produced
c) 0.329 g NH3 remain
d) 4.25 g = 4.25 g
Moles76. 5.24 g H2SO4 6.99 g PbSO4
2.77 g HC2H3O2
78. C2H6 + Cl2 C2H5Cl + HCl
232 g C2H5Cl (theoretical yield)
88.8% yield
80. Actual yield of Na2S = 1.80 g (1.95 g is the theoretical yield)
Moles
The atmosphere of Jupiter is composed almost entirely of hydrogen (H2) and helium (He). If the average molar mass of Jupiter’s atmosphere is 2.254 g/mole, calculate the percent composition.
Moles