December 04, 2020, 02:38:19 PM
Forum Rules: Read This Before Posting

### Topic: Gas laws questions  (Read 97 times)

0 Members and 1 Guest are viewing this topic.

#### Win,odd Dhamnekar ##### Gas laws questions
« on: November 19, 2020, 07:41:41 AM »
Question 1) The critical temperature for  water is 647.1 K. At $10^3$ bar and 700 K, the density of supercritical water is $651.37 kg m^3$. Note that this is about 68% of the value for liquid water at the boiling point at 1 bar. What is the molar volume in $m^3mol^{-1}$ of water at this temperature and pressure? in L/mol?

Question 2)
Refer to your results in the question 1). Assuming that a water molecule excludes other water molecules from a cubic region centered on itself, estimate the average distance between nearest-neighbor  water molecules in supercritical water at $10^3$ bar and 700 K.

Question 3) Calculate the molar volume of supercritical water at $10^3$ bar and 700 K from the ideal gas equation. What is the error, expressed as a percentage of the value, you computed in question 1)?

Question 4) At 700 K, the virial coefficient B* for water is  $-1.1512\times 10^{-8} Pa^{-1}$. Calculate the molar volume of supercritical water at $10^3$ bar and 700 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)?

Question 5) Calculate the molar volume of supercritical water at $10^3$ bar and 700 K from van der waals' equation. The van der waals' parameters for water are $a= 5.537 bar L^2/mol^2, b=0.0305 L/mol$ What is the error, expressed as a percentage of the value you computed in question 1)?

Question 6) Comment on the results in questions 2ꟷ5.

I don't know  molar mass of supercritical water. That's why i couldn't compute its molar volume $m^3/mol$ and L/mol.

If we know answer to question 1), remaining questions can be answered easily except question 6)

« Last Edit: November 19, 2020, 08:53:07 AM by Win,odd Dhamnekar »
Any science consists of the following process.
1) See2)Hear 3) Smell if needed4) Taste if needed
5) Think 6) Understand 7) Inference take decision [Believe or disbelieve, useful or useless, healthy or unhealthy, cause or effect, favorable or unfavorable, practical or theoretical, practically possible or practically impossible or any other required criteria]

#### chenbeier

• Sr. Member
•     • Posts: 1208
• Mole Snacks: +90/-21
• Gender:  ##### Re: Gas laws questions
« Reply #1 on: November 19, 2020, 07:52:41 AM »
I think molar mass of water will not change by physical changes. Its H2O and it is defined by the atoms in the molecule.