**Laboratory
Techniques For learning objectives of this lab,
click here.**

An introductory
lab that helps familiarize students with the virtual
laboratory environment, and works through the operation
of the mouse, the balance, and some additional apparatus. The
lab explains the virtual lab flow and general rules about entering
data and discussion answers.

*Required
background:* Students will need basic computer skills (using
the mouse and its buttons, a keyboard, etc) and understand the
use of an analytical balance to measure mass.

**Error and Standard
Deviation For learning objectives of this
lab, click here.**

This experiment
provides an introduction to error analysis by calculating the
standard deviation of a group of measured values that exhibit
random deviation about an average value.

*Required
background:* Students should be able to: compute an average
(mean) value, evaluate algebraic expressions and construct a table
of values; use the virtual analytical balance to measure mass.
Experience in the use of a spreadsheet program to assist in the
calculations is helpful but not required.

**Spreadsheets and Linear
Regression For
learning objectives of this lab, click here.**

This experiment
provides an introduction to the use of a spreadsheet program to
analyze an experimental data set by creating a data table and
plotting the data, followed by determining the slope, intercept,
and equation for the best-fit line using the method of least
squares. The best fit linear equation is used to predict new
values.

*Required
background:* Students should be familiar with the basic
operations in a spreadsheet program such as OpenOffice Calc or
Microsoft Excel. Instructions will be provided to install the free
OpenOffice suite of programs if needed. Students should know how to
switch back and forth between two different programs running in
computer memory and be able to keep a useful lab notebook record
during the experiment.

**Combustion ** **For learning objectives
of this lab, click here.**

This experiment
simulates a typical carbon-hydrogen analysis procedure used to
determine the empirical formula of a combustible organic compound.
A measured mass of a pure compound is burned in excess oxygen in a
combustion chamber, and the resulting CO2 and water vapor are
captured in traps. The discussion guides the analysis of trap mass
changes to the calculation of an empirical formula. Both known and
unknown compounds are analyzed in the experiment.

*Required
background:* Students should be able to use the virtual
analytical balance to determine masses, perform stoichiometric
calculations to convert moles to masses and v.v., and understand
the difference between an empirical and a molecular formula.

**Metal +
HCl For learning objectives of this lab, click
here.**

This experiment
uses the pressure of hydrogen produced by the reaction of a known
mass of a metal with excess hydrochloric acid to determine the
atomic mass of the metal. Both known and unknown compounds are
analyzed in the experiment.

*Required
background:* Students should be able to balance chemical
reactions to predict a mole ratio of reactants and products.
Knowledge of the ideal gas equation is also required to convert
pressure data into moles of gas.

**Calorimetry ** **For learning
objectives of this lab, click here.**

This experiment
uses a virtual calorimeter to measure the heat evolved when a
measures mass of a combustible substance is burned in an excess of
oxygen gas. The goal is to determine the heat of combustion per
mole of a known and unknown compound.

*Required
background:* Students should be able to extrapolate graphical
data to obtain a measured temperature change under conditions of
competing trends and calculate heat changes using simple
thermodynamic relations.

**Synthesis and
TLC For learning objectives of this lab, click
here.**

Students
explore the concepts of limiting reagents and stoichiometric ratios
of reactants by running a simple 1:1 organic addition reaction and
using thin layer chromatography on the product obtained to
determine if either reagent was used in excess.

*Required
background:* Students should be familiar with concepts such as
stoichiometric ratios of reactants and limiting reagents. Also
required are calculating a liquid mass from its density and volume,
calculating moles from mass and molecular weight, and a basic
understanding of solvent-solute interactions.

**Absorbance For learning objectives of this lab, click
here.**

This experiment
introduces the principles of absorption spectrophotometry and use
of the Beer-Lambert Law to determine concentration from a working
curve of absorbance vs. concentration.

*Required
background:* Students should be familiar with the properties of
light and the electromagnetic spectra, calculations involving
molarity, and the use of spreadsheets to plot data and determine
the slope, intercept, and equation of a best-fit line.

**NMR For learning objectives of
this lab, click here.**

This experiment
uses 19F nuclear magnetic resonance to determine the structures of
several sulfur fluorides. The number of peaks and their relative
intensities for a series of compounds containing fluorine and
methyl ligands around a central sulfur atom are used to assign
reasonable coordination geometries (octahedral, square planar, and
tetrahedral), and ligand configurations (cis and trans)
configurations.

*Required
background:* Students should be familiar with molecular
geometries of molecules containing a single central atom surrounded
by 4 to 6 ligands. No prior experience with NMR is required.

**Freezing Point
Depression ****For learning objectives
of this lab, click here.**

This experiment
determines the freezing points of pure benzophenone and of a
mixture of another organic substance dissolved in benzophenone. As
these melted mixtures are slowly cooled, the melts begin to freeze,
and the colligative property of freezing point depression is
studied quantitatively.

*Required
background:* Students should be familiar with the colligative
property of freezing point depression, the definition of molality,
and the parameters relating freezing point depression to
molality.

**Osmotic
Pressure For learning objectives of this lab, click
here.**

This experiment
introduces semi-permeable membranes as a means of measuring the
osmotic pressure of aqueous solutions of several soluble
substances. A membrane osmometer is used for these quantitative
measurements.

*Required
background:* Students should be familiar with the colligative
property of osmotic pressure, the definition of molarity, and the
parameters relating osmotic pressure to molarity.

**Thin Layer
Chromatography For learning
objectives of this lab, click here.**

This experiment
studies in greater depth the technique of Thin Layer Chromatography
(TLC) that was introduced as a tool in the Synthesis experiment.
TLC relies upon the interactions between a solvent, a solute, and a
stationary substrate. The competition between solvent and solute
molecules for sites on the stationary phase determines the relative
rates at which different solutes move along the substrate while
being transported by the solvent, allowing different substrates to
be separated and identified.

*Required
background:* Students should be familiar with the shapes of
organic molecules, chemical bond polarity, the role of molecular
shape in determining overall molecular polarity, and functional
groups in organic molecules. Precise use of the mouse to click and
drag objects in the virtual lab will be required.

**Iodine
Clock ** For learning objectives of this lab,
click here.

Students will
set up and run multiple instances of the classic "iodine clock"
reaction with different reagent concentrations to evaluate the
reaction rate law exponents.

*Required
background:* Students should be familiar with standard kinetic
terms such as reaction rate, rate law, and the relationship
between reaction time and reaction rate. Students need to calculate
molarities and be able to use the expression M1V1 = M2V2 to
calculate the effects of dilution. Use of the log function and use
of a spreadsheet program to plot data and determine a slope are
required.

**Titration
I For learning objectives of this lab, click
here.**

This experiment
introduces the concept of "standardization" of a solution by use of
a primary standard reagent and an acid-base titration. The pH of an
acid solution is monitored using a pH electrode and a titration
curve plotted in real time (pH vs volume of added base). The
experimental determination and significance of the "endpoint" is
illustrated.

*Required
background:* Students should be familiar with the definitions
of strong acid/base and weak acid, the reaction of an aqueous
acidic solution with a basic solution, the definition of pH, how to
measure the mass of a reagent to be dissolved in solution, how to
calculate concentration (Molarity) of a solution based upon the
calculated moles of reagent and volume of solution, as well as be
able to use the expression M1V1 = M2V2 to calculate the
concentration of a reagent involved in a known reaction with a
given solution, and be able to calculate an average and the
standard deviation of several measurements.

**Titration
II ****For learning objectives of this lab,
click here.**

This experiment
uses the titration technique introduced in the Titration I
experiment to measure the concentration of a weak acid solution
using a strong base of known concentration. From these results, the
weak acid's molar mass and acid dissociation constant, Ka, are
determined.

*Required
background:* Students should be familiar with the titration
scheme from the Titration I experiment, the definition and general
behavior of weak acids, the use of Ka in calculating pH, and how to
use the measured endpoint of a titration in calculations.

**Weak Acid
Equilibrium ****For
learning objectives of this lab, click here.**

This experiment
studies in depth the behavior of a weak acid and its conjugate base
by forming aqueous solutions of several known compositions and
measuring pH. Buffer solutions are created and buffer capacity
described. Each prepared solution is tested by adding small amounts
of strong base to observe relative pH changes.

*Required
background:* Students should be familiar with the definitions
of weak acid, conjugate base, buffer, strong base, pH, and how to
calculate solution concentrations.

**Electroplating ****For
learning objectives of this lab, click here.**

This experiment
involves the reduction of metal ions in an aqueous solution to
plate metal on an electrode. The mass of plated metal is measured
and compared to the amount of electric charge used to reduce the
ions. A known metal is tested, and the identity of an unknown
metallic element is determined by calculating the charge required
to plate a measured metal mass.

*Required
background:* Students should be familiar with oxidation and
reduction, half-reactions, Faraday's Law, The relationship of
current and charge, and the dissociation of ionic compounds into
ions in solution.

**Potentiometry ****For learning
objectives of this lab, click here.**

This experiment
allows students to generate electrochemical cells with separate
half-reactions and measure the cell potentials. Observed values are
compared to literature values, the effect of concentration is
evaluated, and an unknown metal ion in solution is identified by
the cell potential produced against a known half-cell.

*Required
background:* Students should be familiar with oxidation and
reduction, half-reactions, and calculations involving the Nernst
equation.

**Nuclear
Chemistry ****For learning objectives
of this lab, click here.**

This experiment
uses neutron activation in a virtual nuclear reactor to measure the
decay half-life of two unstable isotopes.

*Required
background:* Students should be familiar with the concepts of
exponential decay, the first order rate law, half-life, and the use
of logarithms.

**Entropy ****For
learning objectives of this lab, click
here.**

This experiment
extends the Potentiometry experiment by adding temperature control
and variation. By measuring the potential of several
electrochemical cells at different temperatures, the Gibbs free
energy, enthalpy, and entropy changes for reactions are
determined.

*Required
background:* Students should be familiar with the Potentiometry
experiment, the use of free energy of formation, enthalpy of
formation, and entropy, calculations using the relationships
ΔG=ΔH‐TΔS and ΔG=-nFE. Students will use a spreadsheet program to
plot data and obtain the slope and intercept for a best-fit
line.

**Density ****For
learning objectives of this lab, click
here.**

This experiment
introduces density as an intensive property of a few regular
solids. After measuring the mass and determining the volume of
objects, the student calculates the densities. Gold alloys are used
as examples of materials with similar appearance but different
densities.

*Required
background:* Students should be familiar with the formula for
the volume of common regular objects (cube, cylinder, and
sphere).

**Vitamin-C
Analysis ****For learning objectives
of this lab, click here.**

This experiment
provides an introduction to the analysis of concentration without
background in stoichiometry. Titration to a colored endpoint is the
method. After standardization of the titrant DCP using a vitamin-C
solution of known concentration, the student proceeds to determine
the vitamin-C content in drinks, juices, and fruits.

*Required
background:* Students need only simple arithmetic skills and
the ability to perceive color change to red-pink.