The heat of vaporization of acetone is 31.3 kJ/mol,and a a boiling point of 78.6° at 1520 mm Hg.What is the boiling point when the pressure is raised to 7600 mm Hg?

Question

Quizplus · Accepted Answer

First, we need to calculate the vapor pressure of acetone at its boiling point of 78.6°C at 1520 mm Hg. We can use the Clausius-Clapeyron equation:

ln(P2/P1) = (ΔHvap/R) * (1/T1 - 1/T2)

where P1 and T1 are the initial pressure and boiling point (1520 mm Hg and 78.6°C), P2 is the final pressure (7600 mm Hg), ΔHvap is the heat of vaporization (31.3 kJ/mol), R is the gas constant (8.314 J/mol*K), and T2 is the unknown final boiling point.

Converting the temperatures to Kelvin and plugging in the values, we get:

ln(7600/1520) = (31.3*10^3/8.314) * (1/351.75 - 1/T2)

Solving for T2, we get:

T2 = 414.15 K = 141°C

So the boiling point of acetone at 7600 mm Hg is 141°C, or choice D.

The Heat of Vaporization of Acetone Is 31