1. Chapter 4 Skills Balance Equations for simple chemical reactions
Perform stoichiometry calculations using balanced chemical equations
Mass relationships
Amounts tables
Understand the impact of a limiting reactant on a chemical reaction
Calculate the theoretical and percent yields of a chemical reaction
Stoichiometric uses
Analysis of mixtures
Determination of empirical or molecular formulas
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Kull Chem 105 Chapter 2

2. Cation Anion Name Formula ammonium bromide Li+ LiClO4 Fe2+ Cl-
lead(II) fluoride
Al3+
AlPO4
lithium bromide
Ba2+
BaS
NO3-
barium nitrate
Ba(NO3)2
Al2(CO3)3
O2-
aluminum oxide
Al2O3
Fe3+
iron(III) oxide
Fe2O3
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boron triiodide
S2Cl2
tetraphosphorus trisulfide
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3. tetraphosphorus trisulfide P4S3
Cation
Anion
Name
Formula
NH4+
Br-
Ammonium bromide
NH4Br
Li+
ClO4-
Lithium perchlorate
LiClO4
Fe2+
Cl-
iron(II) chloride
FeCl2
Pb2+ F-
Lead(II) fluoride
PbF2
Al3+
PO43-
aluminum phosphate
AlPO4
Lithium bromide
LiBr
Ba2+
S2-
Barium sulfide
BaS
NO3-
Barium nitrate
Ba(NO3)2
(CO3)2-
Aluminum carbonate
Al2(CO3)3
O2-
Aluminum oxide
Al2O3
Fe3+
Iron(III) oxide
Fe2O3
---
boron triiodide
BI3
disulfur dichloride
S2Cl2
tetraphosphorus trisulfide
P4S3
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4. Understand the impact of a limiting reactant on a chemical reaction
20. ■ Ammonia gas can be prepared by the reaction of a metal oxide such as calcium oxide with ammonium chloride.
CaO(s) + 2 NH4Cl(s)  2 NH3(g) + H2O(g) +CaCl2(s)
If 112 g of CaO and 224 g of NH4Cl are mixed, what mass of NH3 can be produced?
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5. Answers
4.20
112 g CaO · = 2.00 mol CaO
224 g NH4Cl · = 4.19 mol NH4Cl  CaO has fewer moles and is the limiting reactant 112 g CaO · · · = 68.0 g NH3
Equation
CaO(s) + 2 NH4Cl(s)  2 NH3(g) + H2O(g) + CaCl2(s)
Initial (mol)
Change (mol) – –
Amt after rxn(mol)
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6. Calculate the theoretical and percent yields of a chemical reaction
30. A reaction studied by Wächtershäuser and Huber (see “Black Smokers and the Origins of Life”) is
2 CH3SH + CO  CH3COSCH3 + H2S
If you begin with 10.0 g of CH3SH, and excess CO,
(a) What is the theoretical yield of CH3COSCH ?
(b) If 8.65 g of CH3COSCH3 is isolated, what is its percent yield?
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7. Answers 4.30 (a) 10.0 g CH3SH · · · = 9.37 g CH3COSCH3
(b) · 100% = 92.3% yield
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