Please answer all equations with equations used.

terfacial Tension problems 3. Evaluate the interfacial tension for propane at Tr=0.7 4. Evaluate the interfacial tension for a mixture methane and octane at 280F at 4 different pressures. 5. Evaluate the interfacial tension for the following gas-liquid equilibrium mixture at T=280F and P=1,200 ssia The oil and gas densities are 34.65lb/ft3 and 5.67lb/ft3 respectively and the compositions are