Problem 4. Clausius-Clapeyron equation provides a good approximation for the heat of vaporization at low pressures. Estimate the heat of vaporization for n-butane at Tr=0.75. The vapor pressure for n butane for a T range of ( 300 to 400K ) can be approximated with the following equation that requires T in K and provides p in bar. (25 points) H=pRT2(dTdpsat)psat=1.961003T21.15T+171.0Tc=425.125KR=8.3145J/Kmol