I think the connection being that if there are more configurations it's more "disordered" which isn't really a precise thing. I don't think you see this definition in a physics education until you do a course on statistical mechanics? I feel like I certainly had teachers say "disorder". When all the configurations are equally probable, you get the formula The definition of entropy from a statistical mechanics perspective, is roughly a count of the number of different (microscopic) configurations, \Omega, of a system. Therefore, there is an increase in entropy associated with the clumping of oil molecules -a totally counterintuitive idea! On the other hand, when the oil molecules clump together, the area of “ordered water” is reduced fewer water molecules are affected. The more oil molecules disperse in the water, the larger the decrease in entropy. This more ordered arrangement results in a decrease in entropy. This cage of water molecules around each hydrocarbon molecule is a more ordered arrangement than that found in pure water, particularly when we count up and add together all of the individual cages! It is rather like the arrangement of water molecules in ice, although restricted to regions around the hydrocarbon molecule. They form a cage-like structure around each hydrocarbon molecule. > When hydrocarbon molecules are dispersed in water, the water molecules rearrange to maximize the number of H-bonds they make with one another. After the reaction, the two are bonded together and can't float around freely from one another.I was looking for more information on the oil/vinegar situation and found this explanation at. In other words the N 2( g) used to float around independently of the H 2 gas molecules. This is expected because we are decreasing the number of gas molecules. It would appear that the process results in a decrease in entropy - i.e. \įrom the balanced equation we can write the equation for ΔS 0 (the change in the standard molar entropy for the reaction): As with other calculations related to balanced equations, the coefficients of each component must be taken into account in the entropy calculation (the n, and m, terms below are there to indicate that the coefficients must be accounted for): The entropy change in a chemical reaction is given by the sum of the entropies of the products minus the sum of the entropies of the reactants. Unlike enthalpies of formation, standard molar entropies of elements are not 0.When comparing standard molar entropies for a substance that is either a solid, liquid or gas at 298 K and 1 atm pressure, the gas will have more entropy than the liquid, and the liquid will have more entropy than the solid.A table of standard molar entropies at 0K would be pretty useless because it would be 0 for every substance (duh!) Standard molar entropy values are listed for a variety of substances in Table T2. the entropy of a pure substance at 298 K and 1 atm pressure). Standard molar entropies are listed for a reference temperature (like 298 K) and 1 atm pressure (i.e. The entropy of a substance has an absolute value of 0 entropy at 0 K. In fact, values for the "standard molar entropy" of a substance have units of J/mol K, the same units as for molar heat capacity. the rise in temperature is the heat capacity, it would seem that in some way, information about the heat capacity (and how it changes with temperature) would allow us to determine the entropy change in a system. Since the quantitative term that relates the amount of heat energy input vs. all the ice has melted or all the liquid has frozen) However, in both of the above situations, the energy change is not accompanied by a change in temperature (the temperature will not change until we no longer have an equilibrium condition i.e. Likewise if a small amount of energy is withdrawn from the system, the equilibrium will shift to the left (more ice).If a small amount of energy is input into the system the equilibrium will shift slightly to the right (i.e.At such a temperature and pressure we have a situation (by definition) where we have some ice and some liquid water.
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