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Physical Chemistry
November 28, 2011
Published by Bryan at November 28, 2011
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At that time, it was customary for a week’s symposium to have an outing. Although it was mid-August, Bob, an avid skier, had planned a trip to Whistler mountain where the participants would take the gondola up to the Round House and spend a couple of hours in the clean mountain air and enjoy the surrounding scene of mountains and glaciers. However the day before the outing, by chance I called Whistler and found that gondola was closed for maintenance and at that time it was the only way up.
November 21, 2011
The basic idea is that a physical system has many different arrangements (states) of particles which are consistent with some macroscopic quantity, like the temperature. Boltzmann found that out of all possible ways those particles can be arranged, only those that are consistent with the actual temperature need be considered. The chance of any other arrangements is negligible in comparison. Rolling dice illustrates this nicely.
November 14, 2011
it is suggested the difficulty students have in understanding that entropy is a measure of randomness can be approached by rolling dice. In the first entry two dice were rolled but in that case there are only 36 arrangements and 10 outcomes (rolls from 2 to 12). This does not show that the most random state dominates (i.e. the one with most number of arrangements consistent with a roll of 7) . To show that more dice need be rolled. In this entry three dice are shown to have more randomness in the outcomes (3 to 18).
November 8, 2011
To understand entropy, I roll dice. I start with two, then move to three, four, ten and then Avogadro’s constant of dice, and roll them randomly.
August 26, 2011
Published by Bryan at August 26, 2011
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In a nutshell Bell thought that different reference frames would allow superluminal communication between particles. Einstein’s special relativity predicts the well-known space and time contractions in different inertial frames, and perhaps these could explain the EPR paradox and rationalize non-locality.
August 5, 2011
Published by Bryan at August 5, 2011
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Explosions are vigorous chemical reactions that take place very rapidly and produce large volumes of gas and a lot of heat. For the explosives shown here, all are solids or liquids with a small volume relative to the huge amount of gas that is released in the explosion. The rapid production of a large volume of gas causes damage.
August 4, 2011
Published by Bryan at August 4, 2011
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The empirical formula is simplest whole number formula for a compound.
August 3, 2011
Published by Bryan at August 3, 2011
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Once atoms were found, it became evident that atoms were composed of protons, neutrons and electrons. The first model, due to J.J. Thomson, was the plum pudding model. This suggested that the atom was a positively charged cloud with electrons floating in it. This model is incorrect.
August 1, 2011
Published by Bryan at August 1, 2011
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At the energy we mostly deal with in chemistry matter is composed of atoms, molecules and ions. From a chemical point of view, these particles interact though the electromagnetic force.
August 1, 2011
Published by Bryan at August 1, 2011
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If we start off with no information and make a guess at something logical, then the development of that idea is mathematics, not science. Science is based upon observation first and after doing experiments, trends may be noticed and we can perhaps summarize the data into a Natural Law.
July 15, 2011
Published by Bryan at July 15, 2011
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The more heat that is converted into work, the more efficient the process. The heat lost to the cold reservoir cannot be recovered. Efficiency is therefore define as the ratio of work out to heat in,...
July 13, 2011
Published by Bryan at July 13, 2011
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The Third Law of Thermodynamics says: if two separated systems are in thermal contact with a third, then at equilibrium they all have the same temperature.
Clearly when we bring two blocks together, heat will flow between them. This is an example of coupling systems A to B and to C so eventually the three will be in equilibrium. This coupling only allows heat to flow through direct contact.