The pressure dependence of the vacancy concentration in a metal at 800C has been determined in a high-pressure experiment for two pressures: At p1 = 1 atm, xv = 1.6010-4 and at p2 = 1,000 atm, xv = 1.4710-4. The self-diffusion coefficients of this metal at 800C have been determined at the same pressures: DMe = 3.0510-8 cm2/s at p1 = 1 atm and DMe = 2.6510-8 cm2/s at p1 = 1,000 atm. a) Calculate the volume of vacancy formation in this metal. b) At what pressure will xv = 1.3010-4? c) What is the value of the activation volume of motion?