Chemistry 360 Dr. Jean M. Standard Problem Set 6 Solutions 1. Three moles of an ideal gas expand isothermally and reversibly from 90 to 300 L at 300 K. (a) Calculate â¬ Î´ U m, â¬ mÎ S m, w per mole, and q per mole. For an ideal gas, â¬ Î´ U = C v T, or in terms of molar quantities, â¬Î´ U m = C v, m Î´ T.inally, since â¬ dS = dq rev T, for an isothermal process, the molar entropy change is â¬ Î´ S m = q m T = 3003J/mol300KÎ S m = 10.01Jmol â1 K â1. (b) If the expansion is carried out irreversibly by allowing the gas to expand rapidly into a vacuum, determine â¬ Î´ U m, â¬ S m, w per mole, and q per mole.
Almost every modern piano has 52 white keys and 36 black keys for a total of 88 keys (seven octaves plus a minor third, from A0 to C8). Many older pianos only have 85 keys (seven octaves from A0 to A7). Some piano manufacturers have extended the range further in one or both directions.
Notes of the Black Piano Keys. Black piano keys are called accidentals; these are the sharps and flats of the piano. On the keyboard, there are five black accidentals per octave. A sharp makes a note a half step higher in pitch. A flat makes a note a half step lower in pitch. On the keyboard, a noteâs flat is the black key directly to its left.