Specific volume and enthelpy of mercury

[jahanzebikram]

Homework Statement

"Determine the specific volume and enthalpy of mercury at 0.4 MPa and 55% quality."

Relevant Equations

Q = m c dT

I have been away from thermodynamics for a while, and there is a young mechanical engineering student who asked my help in solving the question. For the life of me I am unable to solve this problem and I am at my wit's end.

I believe I can solve the problem if some pointers are provided. Also, do property tables (like steam tables) for mercury exist?
If nothing else, then can I be directed towards the relevant study material? Any help is much appreciated.

 

[Chestermiller]

Google "Mercury thermodynamic properties"

 

[erobz]

Homework Statement:: "Determine the specific volume and enthalpy of mercury at 0.4 MPa and 55% quality."
Relevant Equations:: Q = m c dT

I have been away from thermodynamics for a while, and there is a young mechanical engineering student who asked my help in solving the question. For the life of me I am unable to solve this problem and I am at my wit's end.

I believe I can solve the problem if some pointers are provided. Also, do property tables (like steam tables) for mercury exist?
If nothing else, then can I be directed towards the relevant study material? Any help is much appreciated.

Well, I don't know if this helps (because I can't find "Satutrated Mercury Tables (liquid - vapor)", But let's pretend they do exist and it's just a matter of finding them.

To just refresh on the mechanics of that process: What do you get for the enthalpy of Saturated Water @ 4 Bar, 50% Quality?

 

[jahanzebikram]

Well, I don't know if this helps (because I can't find "Satutrated Mercury Tables (liquid - vapor)", But let's pretend they do exist and it's just a matter of finding them.

To just refresh on the mechanics of that process: What do you get for the enthalpy of Saturated Water @ 4 Bar, 50% Quality?

If I am not mistaken the enthalpy of Saturated water @ the given properties should be determined like this:

@ 4 bar
hf = 604.68 kJ/kg
hg = 2737.63 kJ/kg

so at x = 0.5

h = (1-x)hf + (x)hg
h = (0.5)604.68 + (0.5)2737.63
h = 1671.155 kJ/kg

but after a lot of googling, I have been unable to find saturated mercury tables so maybe there is some different way of finding out the solution that I don't have any idea about. Like I said, I have been away from thermodynamics for a while, and this question seemed like something I should be able to solve but can neither find head nor tails of it.

 

[jahanzebikram]

Google "Mercury thermodynamic properties"

After being unable to hone the powers of "lord google", I turn to you to get me out of this sticky problem.

 

[Steve4Physics]

No expert, but a few thoughts about finding the specific volume.

Presumably we take 0.4MPa (about 4 atm) to be the vapour pressure. In this case, the system’s temperature can be read-off this graph:
https://i.stack.imgur.com/StSNl.gif

The graph is Figure 1 from this pdf document: https://www.physics.rutgers.edu/~eandrei/389/NISTIR.6643.pdf

We now know the temperature and pressure of the vapour and we can find its specific volume (e.g. maybe using the ideal gas equation, else Van der Waals equation with the appropriate constants for mercury).

We can easily find the specific volume for the liquid phase. So the overall specific volume can be determined.

Not sure if that is what’s intended though. Seems a bit convoluted!

And if I’ve misunderstood something, I’m sure someone can correct me.