*USING MATLAB ONLY* Please post screenshots

Yaws Critical Property Data for Chemical Engineers and Chemists recommends the following equation to compute the surface tension of saturated organic

compounds (i.e., organic compounds at vapor/liquid equilibrium): =A+BT+CT²+DT3+ET4+FT5

where is the surface tension in units of N/m, T is the temperature in K, and A, B, C, D, E, F are regressed coefficients. The surface tension is the force per unit length needed to separate the molecules at the vapor/liquid interface. It can equivalently be related to the vapor/liquid free energy barrier per unit area:

= (1F) / (2A)

At the critical point, the two phases become one, and the vapor/liquid free energy barrier and hence surface tension go to zero. This is a famous property that Guggenheim exploited to estimate the critical temperature of compounds. He would measure the surface tension at a range of accessible temperatures, and then extrapolate to where the surface tension went to zero. Cool! compound

compound	A x 102	B x 104	C x 106	D x 108	E x 1011	F x 1014	Tmin [K]	Tmax [K]
propane	4.9138	-0.9349	-0.7665	0.4318	-1.1075	1.1416	86	369.82
ethanol	0.8673	6.6647	-4.7511	1.3783	-1.9592	1.1142	250	513.9

a) Write a script to compute surface tension using the expression suggested by Yaws.

b) Using your script, compute the surface tension of propane and ethanol at a range of temperatures. Does surface tension increase or decrease with increasing temperature? Does the surface tension appear to approach zero at the critical point? (Tmax corresponds to the critical temperature.)

c) Propane is a linear alkane consisting of three methyl groups. We can picture ethanol as propane where one of the terminal methyl groups has been replaced with a hydroxyl group. Comparing the surface tension of propane and ethanol can therefore give us an idea of the difference in intermolecular interaction strength of a methyl and hydroxyl group. Compute the surface tension of propane and ethanol at 300 K, and compare. In which system are the intermolecular interactions strongest?