Caculating normal boiling point using an equation of a line

In summary, the equation for the best fit line is y = -5307.5x + 19.55 and using this equation, the heat of vaporization for the volatile liquid is 44.127 kJ/mol. To calculate the boiling point, the Clausius-Clapeyron equation can be used, which results in a boiling point of 99 C. However, this may not be accurate as it does not consider the conversion of kJ to joules. The next problem in this assignment involves determining the compound based on its normal boiling point and heat of vaporization, with options including ethanol, iso-propanol, and cyclohexane. Based on the data given, it can be determined that the volatile
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Homework Statement



The equation for the best fit line was y = - 5307.5x + 19.55. Using the equation of the best fit line, calculate the heat of vaporization and the normal boiling point (in C) of this volatile liquid. (Hint: What is the value of Pvap when liquid boils at its normal boiling point?

Homework Equations



Heat of vaporization = -(slope x R) R= 8.314 j/mol*k

The Attempt at a Solution




The heat of vaporization is 44.127 kJ/mol, but I'm unsure of how to calculate the boiling point.

I tried using the Clausius-Clapeyron equation to find the boiling point. I got 99 C, but I'm unsure if its right. If it helps, the next problem following this problem lists several compounds and I have to find out what compound it is using the Normal Boiling point and heat of vaporization

Ethanol 78.3 C 42.4kJ/mol
iso-Propanol 82.3 C 45.4 kJ/mol
Cyclohexane 80.7 C 33.1 kJ/mol

I know that its not cyclohexane because its heat of vaporization differs from mines.
 
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  • #2
Actually, the clausius equation doesn't work because I forgot to convert kJ to joules while doing the equation.
 

1. What is the equation used to calculate normal boiling point?

The equation used to calculate normal boiling point is the Clausius-Clapeyron equation, which is ln(P2/P1) = -ΔHvap/RT + C, where P2 and P1 are the vapor pressures at two different temperatures, ΔHvap is the enthalpy of vaporization, R is the gas constant, T is the temperature, and C is a constant.

2. What is the significance of the Clausius-Clapeyron equation in calculating normal boiling point?

The Clausius-Clapeyron equation is significant because it relates the boiling point of a substance to its enthalpy of vaporization, which is a physical property of the substance. This equation allows us to calculate the normal boiling point of a substance without having to physically measure it.

3. Can the Clausius-Clapeyron equation be used for all substances?

No, the Clausius-Clapeyron equation is not applicable to all substances. It is only valid for substances that follow the ideal gas law and have a constant enthalpy of vaporization over the range of temperatures being considered.

4. How accurate is the normal boiling point calculated using the Clausius-Clapeyron equation?

The accuracy of the normal boiling point calculated using the Clausius-Clapeyron equation depends on the accuracy of the vapor pressure data and the enthalpy of vaporization value used in the equation. The more accurate these values are, the more accurate the calculated boiling point will be.

5. Are there any limitations to using the Clausius-Clapeyron equation to calculate normal boiling point?

Yes, there are some limitations to using the Clausius-Clapeyron equation. It assumes that the vapor pressure is directly proportional to the temperature, which may not always be the case. It also assumes that the enthalpy of vaporization is constant over the temperature range being considered, which is not always true for substances with complex molecular structures.

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