Phenol-Water Solubility

[PineappleBurst]

Just some info first.

Phenol and Water is not soluble. At some temperature they are. At others phenol comes a solid, while at others phenol and water are just two phase liquid like oil and water.

 

I'm doing an experiment to plot the solubility curve of Phenol-Water. I was asked to find the eutectic temperature, critical composition, and consolute temperature.

 

Well eutectic point for 2 solids is the lowest temperature they melt, so is it just the lowest temperature phenol-water is soluble?

 

Critical composition I have no clue, any ideas?

 

Consolute temperature, consolute means i don't understand it from dictionary.com

"–adjective Chemistry.

1. (of two liquids) mutually soluble in all proportions.

2. soluble in each of two or more conjugate liquids.

3. of or pertaining to two partially miscible liquids capable of becoming totally miscible under certain conditions. "

 

So is just temperature the two liquids are soluble to each other? (wouldn't that be just the solubility curve itself?)

 

Thanks for reading/answering.

[CaptainPanic]

According to my thermodynamics book (Smith, van Ness & Abbott), chapter 14, the term

"lower consolute temperature" is the same as "lower critical solution temperature".

 

Also, the "higher consolute temperature" is the same as "higher critical solution temperature".

 

See this wikipedia link for an explanation of both.

 

The two points (lower and higher) are the points where the first phase split occurs. Between those two points, two liquid phases can exist.

 

Note that it is not necessary to have both points - it may be that only a higher or lower point exist.

[PineappleBurst]

Thanks for the reply!

 

So just to comfirm, in my case of a solubility curve, the place where the phase boundary exist is the curve itself, so wouldn't the consolute temperature just be that curve?

 

From the link you sent me, a critical point can be of a function composition or temperature. So in this case, then it would be composition where the phase boundary ceases to exist.

 

Since its a solubility curve, from 0% composition to 100% composition, and a relative large range of temperature (100 degree C), wouldn't the curve itself tell me the critical composition at a certain temperature is... or the consolute temperature at a certain composition is...

 

If I think of it in that sense, they would naturally refer to the same thing right?

 

So confused. Thanks for replying again.