What are some questions about thermodynamics and their potential answers?

In summary: Answer to question 2) is just estimation, because water molecule exclude other water molecules from a cubic region centered on itself. Answer to question 3) is just using ideal gas equation. Answer to question 4) is just using virial coefficient. Answer to question 5) is just using van der Waals equation. Answer to question 6) is still unresolved. In summary, these chemistry questions are other math topics.
  • #1
WMDhamnekar
MHB
376
28
Hello,
Here are the questions with unknown answers. (These chemistry questions are other math topics.)
1) At 1 bar, the boiling point of water is 372.78 K. At this temperature and pressure, the density of liquid water is $958.66 kg/m^3$ and that of gaseous water is $0.59021 kg/m^3.$ What are the molar volumes. in $m^3 mol^{-1}$ of liquid and gaseous water at this temperature and pressure? in Liters/mol?

2) Refer to the answer to 1) question. Assuming that a water molecule excludes the other water molecules from a cubic region centered on itself, estimate the average distance between nearest-neighbor water molecules in the liquid and in the gas.

3)Calculate the molar volume and gaseous water at 1 bar and 372.78 K from ideal gas equation. What is the error, expressed as a percentage of the value, you calculated in question 1).

4) At 372.78 K, the virial coefficient B* for water is $-1.487 × 10^{-7} Pa^{-1}$. Calculate the molar volume of gaseous water at 1 bar and 372.78 K from the virial equation: $Z=P\overline{V}/RT= 1+B^*P.$ What is the error, expressed as a percentage of the value, you computed in question 1).

5) Compute the molar volume of gaseous water at 1 bar and 372.78 K from van der Waals' equation. The van der Waals' parameters for water are $a=5.537 bar L^2 mol^{-1}$ and $b=0.0305 L mol^{-1}$. What is the error, expressed as the percentage of the value, you computed in question 1)?

6)What are your comments on the results in questions 3,4 and 5? At this temperature, would you expect the accuracy to increase or decrease at lower pressure?
 
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  • #2
Dhamnekar Winod said:
Hello,
Here are the questions with unknown answers. (These chemistry questions are other math topics.)
1) At 1 bar, the boiling point of water is 372.78 K. At this temperature and pressure, the density of liquid water is $958.66 kg/m^3$ and that of gaseous water is $0.59021 kg/m^3.$ What are the molar volumes. in $m^3 mol^{-1}$ of liquid and gaseous water at this temperature and pressure? in Liters/mol?

2) Refer to the answer to 1) question. Assuming that a water molecule excludes the other water molecules from a cubic region centered on itself, estimate the average distance between nearest-neighbor water molecules in the liquid and in the gas.

3)Calculate the molar volume and gaseous water at 1 bar and 372.78 K from ideal gas equation. What is the error, expressed as a percentage of the value, you calculated in question 1).

4) At 372.78 K, the virial coefficient B* for water is $-1.487 × 10^{-7} Pa^{-1}$. Calculate the molar volume of gaseous water at 1 bar and 372.78 K from the virial equation: $Z=P\overline{V}/RT= 1+B^*P.$ What is the error, expressed as a percentage of the value, you computed in question 1).

5) Compute the molar volume of gaseous water at 1 bar and 372.78 K from van der Waals' equation. The van der Waals' parameters for water are $a=5.537 bar L^2 mol^{-1}$ and $b=0.0305 L mol^{-1}$. What is the error, expressed as the percentage of the value, you computed in question 1)?

6)What are your comments on the results in questions 3,4 and 5? At this temperature, would you expect the accuracy to increase or decrease at lower pressure?

Hello,
Answer to question 1)

Molar volume of liquid water is $0.00001879m^3/mol$

Molar volume of gaseous water is $0.030589 m^3/mol $ using charles' law for temperature-volume relationship.
 
  • #3
Hey Dhamnekar Winod,
What is it that you really want to know?
After all, so far you have merely posted a set of problem statements. And you followed up with what appears to be textbook answers without explanation.
Either way, there are plenty of those in various textbooks.
Is there something that you are stuck on? If so, what is it?
 
  • #4
Klaas van Aarsen said:
Hey Dhamnekar Winod,
What is it that you really want to know?
After all, so far you have merely posted a set of problem statements. And you followed up with what appears to be textbook answers without explanation.
Either way, there are plenty of those in various textbooks.
Is there something that you are stuck on? If so, what is it?
Hi,
I don't know the correct answers to all of these question for verifications. I also don't know how to answer question 2), 5). As question 5) is still unsolved, I can't go further to consider answering question 6).

So, i am studying answers given by learned science professors to similar types of questions. It took much time to answer 1), because i was not knowing that molar mass of gaseous water and liquid water is one and the same, that is 18.02g/mol.
 

1. What is thermodynamics?

Thermodynamics is the branch of physics that deals with the relationships between heat, work, energy, and temperature. It studies how these quantities affect and are affected by each other in various systems.

2. What are the laws of thermodynamics?

The laws of thermodynamics are fundamental principles that govern energy and its transformations. They include the first law (conservation of energy), the second law (entropy always increases), and the third law (absolute zero cannot be reached).

3. What is the difference between heat and temperature?

Heat is the transfer of energy between two objects due to a temperature difference, while temperature is a measure of the average kinetic energy of particles in a substance.

4. How is thermodynamics applied in everyday life?

Thermodynamics has many practical applications, such as in power generation, refrigeration, and cooking. It also helps us understand the behavior of gases, liquids, and solids and how they interact with each other.

5. What are some real-world examples of the second law of thermodynamics?

The second law of thermodynamics states that the total entropy of a closed system always increases over time. A real-world example of this is the dissipation of energy in a car engine, where some of the energy is lost as heat and cannot be converted back into useful work.

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