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.
The modern standard piano has 88 keys. Different from your average piano... There is also type of piano called a Cottage piano which is missing the top and bottom octave of a normal sized 88 key keyboard and hence has 64 keys. There are many other styles of piano with varying numbers of keys. There are two BÃ¶sendorfer pianos that have more than 88 keys: the 7'4 BÃ¶sendorfer 225 has 92 keys, and the 9'6 BÃ¶sendorfer 290 has 97 keys.