August 30, 2013

Physical Chemistry – Overview of Thermodynamics

In one example I use bond energies to calculate the energy per mole of sucrose and TNT (the explosive trinitrotoluene). Most students expect that TNT has more energy, but it turns out the two have about the same. So why is TNT an explosive (actually a conflagration)? TNT burns rapidly and involves a huge volume change. It is the rate of reaction (chemical kinetics) and the rapid volume change that causes the explosive damage. Then I can move to the thermodynamics overview.
March 9, 2011

Millikan’s Oil Drop Experiment

n 1887 J.J. Thomson discovery of the electron was a significant step that led to a much deeper understanding of the microscopic properties of Nature. In this entry, I will discuss the famous Millikan Oil drop experiment which was done in 1909. But recall that in his characterization of the properties of the electron he could only determine the charge to mass ratio, given by -1.76 times ten to the 11th Coulombs per kilogram. Was this ratio a result of two big values or two small values? Robert Millikan was able to separate the ratio in order to show that the ratio was that of two small numbers and in this way he was able to extract the elementary charge and the electron mass. Comparing the electron mass to that of the lightest element, Hydrogen, it is found that the mass of an electron is 1800 times smaller. Indeed at that time this was the smallest particle known.
February 14, 2011

Discovery of the electron

Discussion of the discovery of the electron by J. J. Thomson in 1897 using a cathode ray tube. He was able to obtain the charge to mass ratio, but not the actual mass or charge. Later Millikan was able to separate the two. Indeed Thomson found a new state of matter which laid the foundations for quantum mechanics and a huge range of technologies
February 4, 2010

Chemical Calorimetry

httpvh://www.youtube.com/watch?v=by9piRJElEI In this video step-a by-step description is given of a bomb calorimeter that is used to measure the internal energy of a sample.  If you burn as sample completely and measure the heat that evolves, you can find the thermodynamic internal energy.  Recall that internal energy is a state […]
February 3, 2010

MCH Science E-learning Products : Overview

  httpvh://www.youtube.com/watch?v=FlF6h3H7zLw Summary of MCH High School and College Chemistry and Physics Each of our five courses covers all the material and more that are found in chemistry and physics courses from the high school to College level. The courses entail between 100 and 200 hours of study each.  They […]
February 1, 2010

MCH Science E-Learning Products: Pricing

httpvh://www.youtube.com/watch?v=WXRT_KzjXgk Pricing Our regular prices are about half the cost of hard copy text books and offer much more. There are two types of pricing.  Regular prices and student prices which are discounted 25% by fromm regular pricing.  You can purchase the programs on DVD or by download. The fastes […]

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