Agas obeys the following equation of state: 1) p (v- b) rt+ (apt) where p is the pressure, v is the specific volume, t is the temperature, r is the universal gas constant, and a and b are constants for a gas. (a) [17 points] calculate the entropy change involved when the gas changes from 4 atm and 300 k to 12 atm and 400 k. (b) [8 points] estimate the mean specific heat (cp) at 12 atm. data: m mean specific heat (cp) at 1 atm 8 cal/g value of constant a-1 liter k/atm. mol value of constant b-0.08 liter/mol