Suppose the vapor pressure of a substance is measured at

Problem 11.85Suppose the vapor pressure of a substance is measured at two different temperatures.(a) By using the Clausius Clapeyron equation (Equation 11.1) derive the following relationshipbetween the vapor pressures, P1 and P2, and the absolute temperatures at which they weremeasured, T1 and T2:(b) Gasoline is a mixture of hydrocarbons, a major component of which is octane(CH3CH2CH2CH2CH2CH2CH2CH3). Octane has a vapor pressure of 13.95 torr at 25 °C and avapor pressure of 144.78 torr at 75 C. Use these data and the equation in part (a) to calculatethe heat of vaporization of octane. (c) By using the equation in part (a) and the data given inpart (b), calculate the normal boiling point of octane. Compare your answer to the one youobtained from Exercise 11.80. (d) Calculate the vapor pressure of octane at -30 °C. Step-by-step solution Step 1 of 5 (a)Clausius-Clapeyron equation gives the relationship between vapor pressure, P andtemperature, T as shown below: H In P = vap+ C RTHere, H vapis the molar enthalpy of vaporization, R is the gas constant (8.314 J/mol-K), and Cis a constant.To derive the required equation proceed as follows:Consider two different absolute temperatures (T and1 ) an2two different pressures (P and 1P2. Substitute in the Clausius-Clapeyron equation, and obtain two equations: H vap In P1= RT + C ………(1) 1 In P = H vap+ C ………(2) 2 RT 2