UC知道化学计算，下面有三道化学题，有正确答案，但不知道如何计算，希望高手指点
来源：百度知道 编辑：UC知道 时间：2024/06/24 00:04:06
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 correc
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 correc
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。