Benzene has a heat of vaporization of 30.72 kJ/mol...

Question

Benzene has a heat of vaporization of 30.72 kJ/mol and a normal boiling point of 80.1 oC. At what temperature does benzene boil when the external pressure is 450 torr?

Jules Bruno · Accepted Answer

We’re being asked to determine the temperature at which benzene boil when the external pressure is 450 torrFor this problem, we can use the Clausius-Clapeyron Equation:lnP2P1 = -∆HvapR[1T2-1T1]where: P1 = vapor pressure at T1P2 = vapor pressure at T2ΔHvap = heat of vaporization (in J/mol)R = gas constant (8.314 J/mol•K)T1 and T2 = temperature (in K).[readmore]Note that normal boing point is the temperature at which the vapor pressure of a liquid is equal to 1 atm or 760 torrWe’re given the following values:P1 = 760 torr             T1 = 80.1 oC + 273.15 = 353.25 KP2 = 450 torr            T2 = ??ΔHvap = 30.72 kJ/molWe first need to convert the heat of vaporization from kJ/mol to J/mol:30.72 kJmol×103 J1 kJ = 30720 J/molSolving for T2:ln(450 torr760 torr) =-30720 J/mol8.314 J/mol · K[1T2-1353.25 K]-0.5241 = 3694.97 K[1T2-0.002831 K-1]0.0001418 K-1 = 1T2-0.002831 K-10.002973 K-1 = 1T2T2 = 336 K = 62.85 oC Benzene boils at 62.85 oC when the external pressure is 450 torr

Problem: Benzene has a heat of vaporization of 30.72 kJ/mol and a normal boiling point of 80.1 oC. At what temperature does benzene boil when the external pressure is 450 torr?

FREE Expert Solution

Problem Details

Problem: Benzene has a heat of vaporization of 30.72 kJ/mol and a normal boiling point of 80.1 oC. At what temperature does benzene boil when the external pressure is 450 torr?

FREE Expert Solution

Problem Details

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