4) Chemical Reactions Because S is a state function, the standard molar entropy change for chemical reaction â¬ Î´ S r ! may be calculated using a method similar to that for calculating standard molar enthalpies of reaction, Î´ S r ! = !Î½ i S ii â . (25) In Eq.1) Also, since the heat evolved at constant pressure is the enthalpy change, â¬ q rev = p Î´ H, the entropy change for a phase transition becomes â¬ Î´ S = Î´ HT. (2) Example Determine the standard molar entropy for the following phase transition occurring at 1 bar pressure and 100Â°C, 2â¬ HO (â) â H 2 O (g) .
In the Western tradition of music, there are basically twelve keys, corresponding to the twelve notes of the chromatic scale on a keyboard instrument (ie C, C#, D, D#...etc all the way up to C again). But as these can be either major or minor, we end up with a total of 12 major + 12 minor = 24 possible keys.
But if we include every note in between, there are actually 12 semitones or half tones. So, if we take the key of C, there are actually three main ways of getting from low C to high C; one major scale and two different types of minor scale. You can see them written out below.