EDUCATIONAL APPLETS*
Analytical
Chemistry
 General
Chemistry


Draw plots of the concentration fractions of polyprotic acids species as
functions of pH. 

Draw plots of the concentration fractions of successive complexes
ML, ML_{2}, .... ML_{n} as a function of
log[L]. 

Draw
the titration curves expected for titrations of a number of real acids
and bases at any combination between each other and at any concentration
level. 

Periodic
table of elements and correlation plots of their properties 
Inspect
the numerical values of a number of properties of the chemical elements
and create correlation plots between any two of these properties. [2000/07] 

Instrumental
Chemical Analysis


Observe
the effect of the selected wavelength and of the bandwidth of the
incident radiation beam on the absorbance vs. concentration plot. 

Insert
the empirical formula of an ionic fragment and obtain the relative
intensities of its isotope peaks. Ībserve the lines corresponding to
this fragment, as they would appeared in a mass spectrum. 

Simulated
separation of a mixture of two substances by countercurrent extraction
using a Craig apparatus. 

Simulation
of the separation of a mixture of 5 substances across a chromatographic
column and of the recorded chromatogram. 

Observe the consumption and the production of particles participating in a reversible electrode reaction, their corresponding concentration profiles and
the effect of the potential of the working electrode. 

Instrumentation
 Signal Processing


Analog
electronics: Basic circuits of operational amplifiers 
Examine the operation of the following circuits of operational amplifiers: inverting amplifier, summing amplifier, difference amplifier, differentiator,
and integrator. 

Examine
the 'truth
tables'
of digitals gates and the propagation of logical states through some
simple circuits combining various gates. [2001/04] 

Improve
the signaltonoise ratio of various signals by the moving average,
SavitzkyGolay and ensemble average techniques. 

Observe
the gradual formation of some periodic nonsinusoidal waveforms by
successive pointtopoint additions of sinusoidal functions. 

Obtain the frequency spectrum H(f) of a signal h(t) using a Fast Fourier Transform (FFT), and observe the effect of clipping of certain frequency
bands on the original signal 

Data
Analysis  Chemometrics


Observe the outcome of this statistical test for various pairs of data sets,
which you can easily define. 

Define sets of values of replicate measurements and examine if one of them in each set can be rejected as an outlier or not. [2006/05] 

A
demonstration of the mdegree (m equal or less than 12) polynomial
leastsquares regression on data sets defined by the user. 

Try a nonparametric regression method (Theil's Incomplete Method) to fit a straight line to data points and compare the results with those obtained with
the leastsquares regression method. 

Observe
how Simplex algorithm is searching for the global minimum through a
2dimensional parameter space. 

Observe how the population of the mean values of N measurements, obtained from populations of any distribution, gradually tends to be normally distributed as the number N (sample size) increases. [2005/11] 

An introductory example on Monte Carlo simulations: Calculation of probabilities
of the arrival of a "drunken sailor" to each one
of a town exits.
[2000/04] 
*Applets
are best executed by Microsoft Internet Explorer ver 4.0 or higher.
(page maintained by
Prof.
C. E. Efstathiou)