Problem 6.Enthalpy of Vaporization from Vapor Pressures:A lo

Problem 6.
Enthalpy of Vaporization from Vapor Pressures:
A low melting metallic element has a vapor pressure of 32.6 torr at 436.oC.and a vapor pressure of 492.torr at 718.oC.What is the enthalpy of vaporization of this metal in kJ/mol?
The correct answer is 56.2.
Problem 7.
Vapor pressure is related to temperature:
Ethanol boils at 80 oC.and has a vapor pressure of 393.5 torr at 336.0 oC.At what temperature will it boil under an external pressure of 590.0 torr?
The correct answer is 346.3.
Problem 8.
Enthalpy for changes of state:
A refrigerant with a molecular weight of 138.g/mol has a normal boiling point of 24.1oC.The specific heat for the liquid is 0.825 J/g-K and for the gas is 0.572 J/g-K.The heat of vaporization for the compound is 27.1 kJ/mol.Calculate the heat in Joules required to convert 6.11 g.of this refrigerant from a liquid at 13.6 oC to a gas at 35.6 oC.
The correct answer is 1.29e+3.
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Problem 9.
Vapor Pressure and the Clausius Clapeyron Equation:
Ethanol boils at 78.0 oC.and the enthalpy of vaporization of ethanol is 38.56 kJ/mol.What is the vapor pressure (in mm.Hg.) of ethanol at 43.oC.
Answer example:30.0
Your answer of ------ is incorrect.
The correct answer is 174..

我们来分析一下
第六题：
通过蒸汽压求得蒸发焓
某低熔点金属在436℃时蒸汽压是32.6t,718℃时蒸汽压是492t,求此金属的摩尔蒸发焓
有了这两组数据 带入克拉配龙方程
ln(p2/p1)=△vapH/R*(1/T1-1/T2)
即可求得蒸发焓
其他的等有空了再看.

对的，就是这个意思