Ionic Equations
Advanced Placement 2-Day Science Conference
December 1 - 2, 2000
Houston Airport Marriott Hotel
Houston, Texas
Resources:
Video Discs
CD-ROMs (Mac or PC)
Periodic
Table Live (Special edition 17; J Chem Ed Software)
Articles
Ragsdale, Ronald O.; Zipp, Arden P. Helping students to
improve their approach to predicting the products of chemical reactions.
J. Chem. Educ. 1992 69 390.
Laboratory Experiments
Traditional
Web Based:
Some Web Sites
Lecture on September
25, 2000 Introduction to soluble ionic compounds, the solubility table,
ionic and net ionic equations.
Lecture on September
27, 2000 Double replacement reactions, neutralization reactions and
single replacemetn reactions and writing ionic and net ionic equations.
Pedagogy:
The first reaction my students see occurs on the second day
of class when I define a chemical reaction. The reactions I usually do are;
Fe(s) + S8(s) ---> FeS(s)
Al(s) + Br2(l) ---> AlBr3(s)
(Actually Al2Br6(s))
I show these reactions from videodiscs and have the student
describe what they see. Initially all I'm trying to do is to demonstrate chemical
change. I usually describe these as formation/synethesis reactions.
To help me early on to lay the ground work for chemical reactions
my students begin to memorize several things;
the name and the symbols of the first 20 elements, plus
about thirteen additional common elements;
the formula for ALL of the elements in the periodic table;
the phase of ALL of the elements in the periodic table.
This is the phase of every element at room temperature (25 degrees Celsius).
In the second chapter of most textbooks students must earn
nomenclature, learning monoatomic and polyatomic ions and very simple differences
between ionic and covalent compounds as determined by the formula of the compound.
So I discuss nomenclature of simple binary ionic and binary covalent compounds.
Since they must learn how to write the formulas I discuss how
to use the periodic table to arrive at the most common oxidation state for
the monatomic cations and anions.
I have already told the students to memorize the first 20 elements
in the periodic table and their formula, symbol and name, and 20 additional
common elements. Students are also told to memorize the phase of every element
in the periodic table. In the nomenclature section they are also expected
to memorize the common polyatomic anions and common acids. I also work in
the common bases and the first ten alkanes.
So by the end of Chapter 2 of the text the students are overwhelmed
with a large amount of memorization, but they are also poised to do a considerable
amount of reaction chemistryÉ
Nomenclature of simple binary ionic compounds, symbol and phase
of the elements and the students are able to write an formation reaction for
binary ionic compound. I discuss the periodic table in terms of the Group
I-VIIIA elements. I talk about the magic nature of the noble gas elements
Group VIIIA. Groups IA elements like to lose one electron to have a number
of electrons equivalent to the nearest noble gas. Group IIA like to lose two
electrons, Group VIIA like to gain electrons. The students are told the transition
metals like to lose two or three electrons.
Nomenclature for simple binary covalent compounds, symbol and
phase of the elements and students are prepared to write the formation equation
for several (not many) simple binary organic compounds. H2O, CO2,
CO, NO2, SO2, NH3.
Nomenclature for ionic compounds with polyatomic anions and
we are close to doing all the double replacement reactions. All that is needed
is the solubility table. That comes in by Chapter 4 or 5. I do not discuss
double replacement reactions until I discuss the nature of ionic compounds
in waterÉsolubility and the solubility table.
I always have a pair of laboratories that I have the students
do when IÕm covering this material. One is titled Conductivity, and the other
is titled Solubility.
Nomenclature of simple binary acids and ternary acids, and
simple ionic bases sets up neutralization reactions. While I cover the nomenclature
in chapter 2 I do not discuss neutralization reactions until solution stoichiometry
and titrations.
Since the students know the first ten alkanes they are ready
to handle combustion reaction for hydrocarbons. I add nitrogen and sulfur
containing hydrocarbons and discuss the the new products. I also introduce
alcohols and their combustion products.
Single replacement reactions I do by demonstrations, Group
I elements with water, Group II elements with hydrochloric acid. This semester
I do discuss single of the elemetnal form reacting with a soluble metallic
ionic salt. However, I did not discuss the activity series this semester.
Can view these reactions by going to my Web Site and entering
CHEM1314 as the userid and avogadro as the password.
Chemical Reaction Summary Information
Here are the catagories of commonly selected reactions which
appear on the AP Chemistry Examination
Synthesis (Formation or direct
combination) reactions