Predicting Reactions
Presented by
Mr. Mark Langella
AP Chemistry Instructor
College Board Consultant
2009
Why do the reactions occur?
 Gibbs
Free Energy drives the
Spontaneous reactions



Lower PE energy
Formation of Stronger Bonds
Greater Entropy ( Formation of Gases)
 Solubility
 Formation
Constant
Ways of Expressing
CHEMICAL EQUATIONS
 Word
equation
 In word equations, the names of the
reactants and products are written out.
The following example is a word equation:
 carbon + oxygen carbon dioxide
Formula equations
 Formula
equations consist of formulas
substituted for the names in the word
equation. The reaction above becomes
 C + O2
CO2
Ionic equations

In ionic equations, all water soluble compounds
in an aqueous solution are separated into ions.

2NaI(aq) + Pb(NO3)2(aq)
2NaNO3(aq) + PbI2(s)
2Na+(aq) + 2I-(aq) + Pb2+(aq) + 2NO3-(aq)
2Na+(aq) + 2NO3-(aq) +
PbI2(s)


Spectator ions - Spectator ions do not participate in the
chemical reaction. That is, they are identical on both
sides of the equation.
Net ionic equations
 The
net ionic equation contains all of the
particles in the ionic equation less any
spectator ions.


2Na+(aq) + 2I-(aq) + Pb2+(aq) + 2NO3-(aq)
+ 2NO3-(aq) + PbI2(s)
Pb2+(aq) + 2I-(aq)
PbI2(s)
2Na+(aq)
Balancing

We were reminded (especially by the
combustion reaction above) that the coefficients
used for balancing should be the lowest possible
WHOLE NUMBER coefficients.
 All other rules for the balanced equations are the
same - omit spectator ions, assume a reaction
occurs, write the formulas for molecular
compounds (e.g. HF) as undissociated species
in solution, etc.
Synthesis or Combination
Reactions
 In
synthesis or combination reactions, two
or more substances combine together to
form a single product.
 The general form is A + B
C
 The products must contain only those
elements found in the reactants.
Metal + Nonmetal
 Magnesium
A
Salt
ribbon is burned in oxygen
strip of magnesium metal is heated
strongly in pure nitrogen gas
Synthesis



Solid calcium metal burns in air.
Balanced equation:
(ii) Predict the algebraic sign of entropy change for the reaction.
Explain your prediction.
Online Demos
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Reaction of Magnesium and Oxygen
http://boyles.sdsmt.edu/magburn/magnesium_burning.htm
Reaction of Iron and Sulfur
http://www.pc.chemie.uni-siegen.de/pci/versuche/english/v21-1.html
Reaction of Potassium and Oxygen
http://neon.chem.ox.ac.uk/vrchemistry/FilmStudio/alkalimetals/HTML/pag
e08.htm
Reaction of Lithium and Oxygen
http://neon.chem.ox.ac.uk/vrchemistry/FilmStudio/alkalimetals/HTML/pag
e02.htm
Reaction of Lithium and Chlorine
http://neon.chem.ox.ac.uk/vrchemistry/FilmStudio/alkalimetals/HTML/pag
e04.htm
Reaction of Sodium and Oxygen
http://neon.chem.ox.ac.uk/vrchemistry/FilmStudio/alkalimetals/HTML/pag
e05.htm
Reaction of Zinc and Sulfur
http://boyles.sdsmt.edu/znsulf/zincsul.htm
Nonmetal + Nonmetal Molecular
compounds
 Pure
Solid Phosphorus (White Form) is
burned in air
 Reaction
of Phosphorus and Chlorine

Website:
http://boyles.sdsmt.edu/pwithcl/reaction_of
_white_phosphorus_and.htm
Hydrides
 Preparation
of the Group 1 hydrides
 These are made by passing hydrogen gas
over the heated metal. For example, for
lithium hydride:
 2Li (s) + H2(g)
2LiH
Nonmetal Oxide + Water
 Oxy
Oxyacid
Acid= Contains H+ ions attached to
common Polyatomic ion of Nonmetal
Oxide plus one more oxygen
 Solid dinitrogen pentoxide is added to
water
 Sulfur trioxide gas is bubbled into water
Nonmetal Oxide + Water
Oxyacid
 Phosphorus
(V) oxide powder is sprinkled
over distilled water
 Sulfur
water
dioxide gas is bubbled into distilled
Nonmetal oxide + Oxygen
 (c)
Samples of nitrogen monoxide gas and
oxygen gas are combined.
 (ii)
If the reaction is second order with
respect to nitrogen monoxide and first
order with respect to oxygen, what is the
rate law for the reaction?
Metal oxide + water
metal hydroxide

Solid Cesium Oxide is added to water

Solid sodium oxide is added to distilled water

Powdered strontium oxide is added to distilled
water

Calcium oxide powder is added to distilled water

Solid barium oxide is added to distilled water
Metal Oxide and Water
 Solid
potassium oxide is added to water.
 (i) Balanced equation:
 (ii)
If a few drops of phenolphthalein are
added to the resulting solution, what would
be observed? Explain.
Demo
Cmd
Na2O
MgO
Al3O2
SiO2
P4O10
SO3
Cl2O7
%Ionic
79
68
56
45
32
17
2
Solid
Ionic
Ionic
Ionic
Network
Molecular
Molecular
Molecular
Hydroxide
Formula
NaOH
Mg(OH)2
Al(OH)3
Si(OH)4
OP(OH)3
O2S(OH)2
O3Cl(OH)
SiO2+2H2O
H3PO4
H2SO4
HClO3
Slightly
acidic
Acidic
Stronger
Acid
Very Acidic
Formula
Very
Basic
Basic
Ampho.
Hydrogen-Nonmetal + Water
 Hydrogen
Acidic Solution
Chloride gas bubbled into water
Metal oxide + nonmetal oxide Yields
metal ion attached to common polyatomic ion
 Metal
oxide + carbon dioxide
carbonate

metal
Carbon dioxide gas is passed over hot, solid
sodium oxide
 Metal
oxide + sulfur dioxide
Metal
sulfite

Sulfur Dioxide is passed over solid calcium oxide
DECOMPOSITION REACTIONS
 Substances
break down by means of
decomposition reactions
 The general form of a decomposition
reaction is

C
A+B
 Decomposition reactions are the opposite
of combination or synthesis reactions
Decomposition of Metal Carbonate
 Heating
a metal carbonate always yields
the metal oxide and carbon dioxide.
 MCO3
MO + CO2
 Powdered magnesium carbonate is
heated strongly
 Solid calcium carbonate is strongly heated
Metal Hydrogen Carbonate
Decomposition
 Heating
a metal bicarbonate gives the
metal oxide, carbon dioxide, and water.
 MHCO3
MO + H2O + CO2
 http://www.chemguide.co.uk/inorganic/gro
up1/compounds.html
 Solid
Sodium Hydrogen Carbonate is
strongly heated
Heating the nitrates

Most nitrates tend to decompose on heating to give the metal oxide,
brown fumes of nitrogen dioxide, and oxygen.

For example, a typical Group 2 nitrate like magnesium nitrate
decomposes like this:
2 Mg(NO3)2 =
2 MgO + 2 NO2 + 3 O2

In Group 1, lithium nitrate behaves in the same way - producing
lithium oxide, nitrogen dioxide and oxygen.

The rest of the Groups, however, don't decompose so completely (at
least not at Bunsen temperatures) - producing the metal nitrite and
oxygen, but no nitrogen dioxide.
Decomposition of Metal Hydroxides
 Heating
a metal hydroxide gives the metal
oxide and water
 MOH
MO + H2O
Metal Sulfite Decomposition
 Heating
a metal sulfite produces a metal
oxide and sulfur dioxide
 MSO3 MO + SO2
 Solid calcium sulfite is heated in a vacuum
Metal Chlorate Decomposition

Heating a metal chlorate gives the metal
chloride plus oxygen.
 MClO3
MCl + O2
Decomposition
 Solid
potassium chlorate is strongly
heated.

Question: What is the oxidation
number of chlorine before and after the
reaction occurs?
Electrolysis of Binary Compound
 Electrolysis
of a molten salt (ionic
compound) separates the substance into
its elements.
 MN
M+N
Ammonium Compound
Decomposition

Ammonium
Carbonates
 Solid ammonium
carbonate is heated
(NH4)2CO3

=
2NH3 + 2CO2 + H2O
Ammonium Hydroxide
NH4OH  NH3+ H2O
2007 Questions
(NH4)2CO3
=
2NH3 + 2CO2 + H2O
Peroxide Decomposition
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Elephant’s Toothpaste
Website:
http://boyles.sdsmt.edu/tp
aste/elephants.htm
Genie in a Bottle Demo
Website:
http://boyles.sdsmt.edu/g
eniebot/genie.htm
Do not forget Group I
Peroxides
Reactions Based on Reduction Potentials
EMF Potential
 Reduction

and Oxidation
Single replacement
Cation Replacement
 There
are two types of single replacement
reactions, in one, a metal or hydrogen
replaces a positive ion
 M0 + A+B- M+B- + A0
Replacement of Hydrogen
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Reaction of Magnesium and Different Concentrations of Acids
Website: http://boyles.sdsmt.edu/kinetic/mercadokinetics.htm
Hydrochloric Acid(g) + Magnesium(s)  Magnesium(II)Chloride(aq)
+ Hydrogen(g)
2HCl(g) + Mg(s)  MgCl2(aq) + H2(g)
Small piece of sodium metal is added to distilled water
Website:
http://boyles.sdsmt.edu/sodwat/reaction_of_sodium_and_water.htm
Sodium(s) + Water(l)  Sodium Hydroxide(aq) + Hydrogen(g)
2Na(s) + 2H2O(l)  2NaOH(aq) + H2(g)

) Reaction of Potassium and Water
Website: http://www.chem.shef.ac.uk/webelementsmoov/K_H2O.mov
Potassium(s) + Water(l)  Potassium Hydroxide(aq) + Hydrogen(g)
2K(s) + 2H2O  2KOH + H2(g)
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A strip of zinc is added to a solution of 6.0-molar hydrobromic acid
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Group I with water video
http://video.google.com/videoplay?docid=2134266654801392897&q=rubidium+water
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2007 Question
Cation Replacement
 Reaction
of Zinc and Tin (II) Chloride

Website:
http://www.chemtopics.com/lectures/unit02
/lecture1/displace.htm
 Zinc(s) + Tin (II) Chloride(aq)  Tin(s) +
Zinc (II) Chloride(aq)
 Zn(s) + SnCl2(aq)  Sn(s) + ZnCl2(aq)
Cation Replacement
 1.
A strip of magnesium metal is added to
an aqueous solution of silver nitrate.

Question: Which substance is
oxidized in the reaction?
Cation Replacement
 Zinc
metal is placed into a solution of
copper (II) sulfate.

Question: Describe the change in
color that the original solution undergoes
as the reaction proceeds.
Thermite Reaction
 2Al(s)
+ Fe2O3 (s)  Al2O3 (s) + 2Fe(l)
 http://boyles.sdsmt.edu/thermite/therm.htm
 http://www2.chemie.uni-
erlangen.de/education/medprak/videos/the
rmit_v.mpg
Cation Replacement
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A solution of copper (II) sulfate is spilled onto a
sheet of freshly polished aluminum metal.
Bar of strontium metal is immersed in a 1.0 M
copper (II) nitrate solution.
A piece of copper wire is placed in a solution of
silver nitrate
A small piece of calcium metal is added to hot
distilled water
A solution of tin (II) nitrate is added to a solution
of silver nitrate
Cation Replacement
A
mixture of powdered iron (III) oxide and
powdered aluminum metal is heat
strongly.
 A bar of zinc metal is immersed in a
solution of copper (II) sulfate
 A piece of nickel metal is immersed in a
solution of copper (II) sulfate
 Solutions of tin (II) chloride and iron (III)
chloride are mixed
Cu+2 (aq) + Fe(s)  Cu(s) + Fe+2
Cu+2 (aq) + Zn(s)  Cu(s) + Zn+2
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Growing Crystals in Gels are a
great activity you can use to
demonstrate single replacement
reactions.
Solutions:
1.
Saturated Sodium
metasilicate- Flinn Scientific (CAT
No. S0102) – Needs to be diluted
to a density of 1.06 g/ml. About
158 ml of the commercial solution
diluted to one liter of solution will
yield a proper density.
2.
Commercial White Vinegar
3.
1.0 M CuCl2 (13.5g/100ml
H2O)
4.
1.0 M Pb(NO3)2
(33.1g/100ml H2O)
Pb+2(aq) + Zn(s)  Zn+2(aq) + Pb(s)
Anion Replacement

In the second, a halogen replaces another
halogen as the negative ion.
 N20 + A+BA+N- + B20

Liquid bromine is shaken with 0.5M sodium
iodide solution

Chlorine gas is bubbled into a solution of sodium
bromide
Anion Replacement
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(a) Chlorine gas, an oxidizing agent, is bubbled
into a solution of potassium bromide at 25°C.
(i) Balanced equation:
(i) Cl2 + 2 Br–  2 Cl– + Br2
(ii) Predict the algebraic sign of ∆S˚ for the
reaction. Explain your reasoning.
(ii) negative, a decrease in entropy as a gas
converts into aqueous and a ion converts into a
liquid
Halogen Replacement
NaClO(aq)  2HCl(aq)  Cl (aq)  NaCl(aq)  H O( )
2
2
Cl (g)  2NaBr(aq)  2NaCl(aq)  Br (aq)
2
2

To prepare a saturated solution of aqueous
bromine, mix equal volumes of 1.28 M NaBr,
1.28 M HCl, and household bleach. Prepare
only as much solution as you need to the activity
in working fume hood to avoid unnecessary
exposure to bromine vapor. There is no need to
store the bromine water since it is easily
prepared. It may also be helpful to mix the
solutions in a clear glass bottle allowing your
students to view the color of elemental bromine.
Discussion:

Since the solubility of bromine in water at 25C is 0.214 moles/liter , a
saturated aqueous bromine solution can easily be prepared as needed by
mixing equal volumes of a 1.28 M sodium or potassium bromide solution, a
1.28 M hydrochloric acid solution, and common household bleach. The
three reagents react according to the equation:
 The reaction between bleach and hydrochloric acid produces elemental
chlorine which then will replace the bromine in sodium bromide producing
bromine and sodium chloride.
 A saturated solution of aqueous chlorine can be prepared in the same
fashion. To prepare 100 ml a saturated aqueous solution of chlorine, mix
1.5 ml of concentrated HCl with 13 ml of bleach in 84 ml of water. The
solubility of chlorine at 25 C is 0.092 M (2)
NaClO(aq)  2HCl(aq)  Cl (aq)  NaCl(aq)  H O( )
2
2
Cl (g)  2NaBr(aq)  2NaCl(aq)  Br (aq)
2
2
2007 Question
Special Red-ox Reactions
 Hydrogen
reacts with hot metallic oxide to
produce the elemental metal and water
 Hydrogen gas is passed over hot iron(II)
oxide powder
 Oxygen react with Metal Sulfides to
produce Metallic Oxides and Sulfur
Dioxide

Copper reacts with
Concentrated Sulfuric
Acid- Based on E0
Cu + 2 H2SO4  CuSO4+SO2+2 H2O

Copper Reacts with
Concentrated Nitric
Acid based on E0
3Cu + 8HNO3  Cu(NO3)2+ NO + 4H2O
Typical Reactions
Oxidation States of Manganese
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Procedure
Place 10 ml of a Water into Four Graduated Cylinders
Place one tablet #1 into each Cylinder
.01 M KMnO4 solution is in four small cylinders labeled
A , B, N ( Place Tablet 1/10 ml water)
To Flask A, Add 10 ml of 3M H2SO4
MnO4- + H+
To Flask B, add 10 ml of 5 M NaOH.
MnO4- + OHTo Flask N add nothing.
MnO4-
Special Redox
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To Flask A add .01M NaHSO3 ( Tablet 2) slowly
till you get a colorless Mn2+ ion.
MnO4- + 5H++ HSO3- 3H2O + 2Mn2+ + 5SO42To Flask N add .01M NaHSO3 ( Tablet 2)until a
brown precipitate forms.
2MnO4- + 3HSO33SO42- + H++ H2O +MnO2
To Flask B slowly add .01M NaHSO3 ( Tablet 2)
until a green solution forms.
2MnO4- + OH-+ HSO32MnO42- + 2H2O +
SO42-
Special Redox
 Sulfite
ion is readily oxidized to sulfate. On
prolonged exposure to air, this oxidation
occurs with atmospheric oxygen:
 2SO32-(aq) + O2(g) --> 2SO42-(aq)
 Sulfite or sulfur dioxide will decolorize
permanganate. This de-colorization serves
as a convenient test for sulfur dioxide:
 2MnO4-(aq) + 5SO2(g) + 2H2O(l) -->
5SO42-(aq) + 2Mn2+(aq) + 4H+(aq)
2007 Question
Special Redox


Hydrogen chloride gas is oxidized by oxygen gas.
(i) Balanced equation:
(i) 2 HCl + O2  H2O + OCl2
 or 4 HCl + O2  2 H2O + 2 Cl2


(ii) If three moles of hydrogen chloride gas and
three moles of oxygen gas react as completely as
possible, which reactant, if any, is present in
excess? Justify your answer.

(ii) O2 in excess; reacting on a 2:1 mole ratio, 3
mol HCl requires only 1.5 mol of O2
)
: Preparing Oxygen from Bleach
 Website:
http://boyles.sdsmt.edu/prepoxyg/preparati
on_of_oxygen_gas_from_b.htm
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Special Redox

An acidic solution of potassium dichromate is
added to a solution of iron (II) nitrate.
 Acidified solutions of potassium permanganate
and iron (II) nitrate are mixed together
 Solution of iron (II) chloride is added to an
acidified solution of sodium dichromate
 A concentrated solution of hydrochloric acid is
added to solid potassium permanganate.
Special Redox

A solution of potassium dichromate is added to
an acidified solution of iron(II) chloride.
 A concentrated solution of hydrochloric acid is
added to solid potassium permanganate.
 Solutions of potassium permanganate and
sodium oxalate are mixed.
 A solution of sodium bromide is added to an
acidified solution of potassium bromate
Reactions Driven by
 Solubility
and Precipitation
 Formation of Gases ( Increase in entropy)
 Formation of Water
 Coordinate Covalent Bond Formation
( Lewis Acid-Base)
 Formation Constants
Formation of Water
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Metal Oxide + an Acid
Salt + Water
Metal Hydroxide + an Acid
Salt + Water
(a special type of reaction called neutralization)
A 0.1 M nitrous acid solution is added to the
same volume of a 0.1 M sodium hydroxide
solution
A 0.02 M hydrochloric acid solution is mixed with
an equal volume of a 0.01 M calcium hydroxide
solution.
Acid Base
 Solid
strontium hydroxide is added to a
solution of nitric acid.
 (i) Balanced equation:
 (ii)
How many moles of strontium
hydroxide would react completely with
500. mL of 0.40 M nitric acid?
Answer
Sr(OH)2 + 2 H+  2 H2O + Sr2+
 (ii) 0.10 mol strontium hydroxide
 (i)
Acid Base
 4.
A solution of Ethanoic (acetic) acid is
added to a solution of barium hydroxide.
 Question:
Explain why a mixture of equal
volumes of equimolar solutions of acetic
acid and barium hydroxide is basic.
Acid Base

Equal volumes of 0.1 M hydrofluoric acid and 0.1
M potassium hydroxide are combined.
 (i) Balanced equation:

(ii) Draw the complete Lewis electron-dot
diagram for the reactant that is the BronstedLowry base in the forward reaction.
Acid Base
 Ammonia
gas is bubbled into a solution of
hydrofluoric acid.

Question: Identify a conjugate acidbase pair in the reaction.
Lewis Acid-Base Reactions (Coordinate
Covalent Bond Formation)
 Ammonia
gas is mixed with hydrogen
chloride gas.
 Methylamine
water
gas is bubbled into distilled
Lewis Acid/ Base
 Phosphine
(phosphorus trihydride) gas is
added to boron trichloride gas.

Question: Which species acts as a
Lewis acid in the reaction? Explain.
Formation of Gas and Water
 Metal
Carbonate + an Acid Salt + Carbon
Dioxide + Water
 Hydrogen iodide gas is bubbled into a
solution of lithium carbonate
 Solid zinc carbonate is added to 1.0 M
sulfuric acid.
 Carbon dioxide and Water- Carbon
Dioxide is easily produced by the reaction
of sodium bicarbonate and vinegar.
Nonmetal Oxide and Metal
Hydroxide
)
Reaction of Carbon Dioxide and
Limewater
 Website:
http://boyles.sdsmt.edu/respira/respir.htm

CO2(g) + Ca(OH)2(aq)  CaCO3(s) + H2O(l)
Water and Gas formation
Metal hydrides + Water Metal
Hydroxide + Hydrogen Gas
 Solid
calcium hydride is added to distilled
water
 Solid
sodium hydride is added to water
Formation of Gas and Water
 Metal
Bicarbonate (Hydrogen Carbonate)
+ an Acid
Salt + Carbon Dioxide +
Water
 Excess hydrobromic acid solution is added
to a solution of potassium hydrogen
carbonate.
PREDICTIONS BASED ON
SOLUBILITY
 If
one or both of the products in the double
replacement reaction is insoluble in
water, the reaction will occur.
SOLUBILITY RULES FOR COMMON IONIC
COMPOUNDS IN WATER
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1. All nitrates, chlorates, and acetates are soluble in water.
Silver acetate is sparingly soluble.
2. Most common acids are soluble in water.
3. All common IA, and ammonium compounds are soluble in
water.
4. All chlorides, bromides, and iodides are soluble in water
except silver, mercury (I), and lead. HgI2 and HgBr2 are insoluble in
water.
5. All sulfates are soluble in water except CaSO4, SrSO4,
BaSO4, PbSO4, Hg2SO4. Ag2SO4 is sparingly soluble in water.
6. All carbonates, phosphates, oxides, and sulfites are insoluble
in water but soluble in dilute acids except the IA and ammonium
compounds.
7. The sulfides of all metals are insoluble in water except the IA,
IIA, and ammonium sulfides.
8. All hydroxides are insoluble in water except the IA, Ca(OH)2,
Sr(OH)2, and Ba(OH)2 hydroxides.
Solubility
A
solution of sodium phosphate is added
to a solution of aluminum nitrate
 A solution of potassium phosphate is
mixed with a solution of calcium acetate
 A solution of sodium Iodide is added to a
solution of lead (II) acetate
 A solution of lead(II) nitrate is added to a
solution of potassium sulfate.
Precipitation
A
solution of nickel (II) bromide is added to
a solution of potassium hydroxide.

Question: Identify the spectator ions
in the reaction mixture.
Precipitate formation

A solution of barium chloride is added drop by
drop to a solution of sodium carbonate, causing
a precipitate to form.
 (i) Balanced equation:

(ii) What happens to the pH of the sodium
carbonate solution as the barium chloride is
added to it?
Solubility Driven
Complex Ion Formation

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



Often an ion in water solution is in a more complex
species, in which the ion is bound to several water
molecules
A complex ion consists of a central ion to which are
bonded two, four, or six neutral or ionic species
called ligands
AMPHOTERIC
Lead and Zinc form complexes with hydroxide
The hydroxides of lead and zinc are soluble in both
acidic and basic solutions
Hydroxides that have this property are called
amphoteric
Halide complexes
Al3+ + 6 F- <----------> [AlF6]3-
2.5 x 104
Al3+ + 4 F- <----------> [AlF4]-1
2.0 x 108
Be2+ + 4 F- <----------> [BeF4]2-
1.3 x 1013
Sn4+ + 6 F- <----------> [SnF6]2-
1.0 x 1025
Cu+ + 2 Cl- <----------> [CuCl2]-1
3.0 x 105
Ag+ + 2 Cl- <----------> [AgCl2]-1
1.8 x 105
Pb2+ + 4 Cl- <----------> [PbCl4]2-
2.5 x 1015
Zn2+ + 4 Cl- <----------> [ZnCl4]2-
1.6
Hg2+ + 4 Cl- <----------> [HgCl4]2-
5.0 x 1015
Cu+ + 2 Br- <----------> [CuBr2]-1
8.0 x 105
Ag+ + 2 Br- <----------> [AgBr2]-1
1.0 x 1011
Ammonia complexes
Ag+ + 2 NH3 <---------->
[Ag(NH3)2]+
1.6 x 107
Zn2+ + 4 NH3 <----------> [Zn(NH3)4]2+
7.8 x 108
Cu2+ + 4 NH3 <----------> [Cu(NH3)4]2+
1.1 x 1013
Hg2+ + 4 NH3 <----------> [Hg(NH3)4]2+
1.8 x 1019
Co2+ + 6 NH3 <----------> [Co(NH3)6]2+
5.0 x 104
Co3+ + 6 NH3 <----------> [Co(NH3)6]3+
4.6 x 1033
Cd2+ + 6 NH3 <----------> [Cd(NH3)6]2+
2.6 x 105
Ni2+ + 6 NH3 <----------> [Ni(NH3)6]2+
2.0 x 108
Tollens reagent
 Formation
of a Silver Mirror
 Website:
http://boyles.sdsmt.edu/agmirror/agmir.ht
m
Cyanide complexes
Fe2+ + 6 CN- <----------> [Fe(CN)6]4-
1.0 x 1024
Fe3+ + 6 CN- <----------> [Fe(CN)6]3-
1.0 x 1031
Ag+ + 2 CN- <----------> [Ag(CN)2]-1
5.3 x 1018
Cu+ + 2 CN- <----------> [Cu(CN)2]-1
1.0 x 1016
Cd2+ + 4 CN- <----------> [Cd(CN)4]2-
7.7 x 1016
Au+ + 2 CN- <----------> [Au(CN)2]-1
2.0 x 1038
Complexes with other monodentate ligands
Ag+ + 2 CH3NH2 <---------> [Ag(CH3NH2)2]+1
7.8 x 106
Cd2+ + 4 SCN- <----------> [Cd(SCN)4]2-
1.0 x 103
Cu2+ 2 SCN- <----------> [Cu(SCN)2]
5.6 x 103
Fe3+ 3 SCN- <----------> [Fe(SCN)3]
2.0 x 106
Hg2+ 4 SCN- <----------> [Hg(SCN)4]2-
5.0 x 1021
Cu2+ 4 OH- <----------> [Cu(OH)4]2-
1.3 x 1016
Zn2+ 4 OH- <----------> [Zn(OH)4]2-
2.0 x 1020
Complex Ion Formation
 Aqueous sodium hydroxide is added to a saturated solution of

aluminum hydroxide, forming a complex ion.
(i) Balanced equation:

(ii) If the resulting mixture is acidified, would the concentration of
the complex ion increase, decrease, or remain the same? Explain.

(a) (i)
Al(OH)3 + OH-  [Al(OH)4](ii) decrease; H+ will neutralize OH- and destroy the
complex

Complex Ion Formation
 Solid
silver chloride is added to a solution
of concentrated hydrochloric acid to form a
complex ion.

Question: Which species acts as a
Lewis base in the reaction? Explain.
Driven by K Formation
Constants





Excess concentrated aqueous ammonia is
added to a solution of nickel (II) bromide
Excess concentrated hydrochloric acid is added
to a 1.0 M solution of cobalt (II) chloride
A drop of potassium thiocyanate solution is
added to a solution of iron (III) nitrate.
Excess concentrated ammonia solution is added
to a solution of nickel (II) sulfate
Excess sodium cyanide solution is added to a
solution of silver nitrate
Balancing Red-Ox Reactions
Red-Ox Continued
Red-Ox Under Basic Conditions
Red-Ox continued
Organic
 Where
in The Curriculum?
 Thermochemistry
 Stoichiometry
 Bonding and Molecular Structure
Combustion
 Hexane

is combusted in air.
Question: When one molecule of
hexane is completely combusted, how
many molecules of products are formed?