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Chemistry Forums for Students => Physical Chemistry Forum => Topic started by: gio on August 10, 2005, 12:26:40 AM

Title: Molar volume in Water
Post by: gio on August 10, 2005, 12:26:40 AM

Since I have to prepare an experiment to present in front of the class (laboratory) my teacher told me to do one about Molar Volume in Water.

So I decided to have water at 50ºC and 1 atm, and since I know the density of the water equal to 0.98804g/cm³ and k (kappa)= 4.4*10^-10Pa^-1.  And I want to prove which is the water's molar volume at those conditions :-\.  

I investigated that k (kappa) equals to 1/P (pressure).  Its hard to know, because I dont know if I assume that is an ideal gas

Thanks for the comments!

Title: Re:Molar volume in Water
Post by: Mitch on August 10, 2005, 12:31:46 AM

I may be confused, but how is water an ideal gas?

Title: Re:Molar volume in Water
Post by: gio on August 10, 2005, 12:32:45 AM

I think I'm wrong...Its not possible to be an ideal gas, indeed ;D

Title: Re:Molar volume in Water
Post by: Mitch on August 10, 2005, 12:34:21 AM

That's what we are here for.

To ask you so many questions, that you figure things out yourself. :)

Title: Re:Molar volume in Water
Post by: gio on August 10, 2005, 12:37:21 AM

But maybe i need someone to guide me on how to solve the question about the molar volume of water, i know that I should use the state equation and there is where k(kappa) appears as the isotermic compresibility, but I dont know how to put the density in that "state equation"

Title: Re:Molar volume in Water
Post by: gio on August 10, 2005, 01:28:18 PM

I think the liquid state of water at 50ºC.  And I think I dont have to count the dependence between k (kappa) with pressure.  I'll better rewrite the problem I have now :

Water at 50ºC and 1 atm, density=0.98804 g/cm³ and k(kappa= isotermic compresibility)=4.4x10^-10 Pa^-1.  
a) Which is the molar volume of the water at 50ºC and 1 atm.

Title: Re:Molar volume in Water
Post by: Donaldson Tan on August 10, 2005, 10:34:06 PM

you don't need kappa. you are given the density of water.

since 1mole of water is 18g, what is the volume of 1mole of water?

Title: Re:Molar volume in Water
Post by: GCT on August 11, 2005, 06:29:25 PM

Quote from: gio on August 10, 2005, 01:28:18 PM

I think the liquid state of water at 50ºC.  And I think I dont have to count the dependence between k (kappa) with pressure.  I'll better rewrite the problem I have now :

Water at 50ºC and 1 atm, density=0.98804 g/cm³ and k(kappa= isotermic compresibility)=4.4x10^-10 Pa^-1.  
a) Which is the molar volume of the water at 50ºC and 1 atm.

what exactly does your experiment/project consist of?  Is this a homework problem?  Try to make your intentions a bit more clear.

Another expression for k is (1/Vm)(RT/P^2)

Title: Re:Molar volume in Water
Post by: Mitch on August 13, 2005, 12:50:15 PM

Quote from: gio on August 10, 2005, 12:26:40 AM

I have to prepare an experiment to present in front of the class (laboratory)

Title: Re:Molar volume in Water
Post by: gregpawin on August 22, 2005, 04:49:37 AM

perhaps you should do something other than to make water warm, especially in front of a easily distracted audience