Calculate the value of h2-h1 for superheated steam between the two states p2=100 bar, t2=320 ºc and p1=100 bar and t1= 650 ºc.

a) compare your answer with the value from the steam tables, which is -961.2 j/g.
b) calculate the value of gr for one mole of water at 100 bar at both 320 ºc and 650 ºc.
c) compare your answer to the value of g obtained from the steam tables.
d) calculate the fugacity of the water vapor in the two states.