Calculate the change in free-energy associated with the formation of a critical spherical nucleus. in pure liquid nickel that is 240 ºC undercooled. The answer should be given in atto-joules with 1 decimal of accuracy. (Note the metric prefix atto is 10-18) Properties of Nickel: Heat of Fusion 2660 J/cm3; Surface Energy 255x10-7 J/cm2 ; Freezing Temperature 1453 ºC, Volume Free Energy -728.99 J/cm3 .

Air inially occupying a volume of 1 m2 at 100 kpa, 27 c undergoes three internally reversible processes in series. process 1-2 compression to 500 kpa during which pv constant process 2-3 adiabatic expanslon to 100 kpa process 3-1: constant-pressure expansion to 100 kpa (a) calculate the change of entropy for each of the three processes. (b) calculate the heat and work involved in each process. (c) is this cycle a power cycle or refrigeration cycle?