chornedsnorkack
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Name for frozen phases
If you freeze a solid out of a solution, and the solid contains water and something else, it is a "hydrate".
Is there any term for solids that have a fixed composition, maximum of melting point, but none of the components is water?
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unionised
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Solvates.
But beware that , like "hydrates" it's a verb as well as a noun.
Words like Etherates and alcoholates get used. Their status is a bit questionable.
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DraconicAcid
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Solvates are also sometimes coordination complexes.
Please remember: "Filtrate" is not a verb.
Write up your lab reports the way your instructor wants them, not the way your ex-instructor wants them.
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j_sum1
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And hydrates aren't?
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DraconicAcid
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Some are, some aren't. Even in some coordination compounds, some of the water is coordinated to the transition metal centre, while other water
molecules are simply stuck in the lattice.
Please remember: "Filtrate" is not a verb.
Write up your lab reports the way your instructor wants them, not the way your ex-instructor wants them.
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chornedsnorkack
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Does "solvate" require you are specifying one but not the other components as "the solvent"?
The system H2O-SO3 is miscible in all ratios above melting point (note that it sublimes near the SO3 end).
The maximum melting point compositions are customarily, with some evidence, designated:
H2O
H2SO4*4H2O
H2SO4*2H2O
H2SO4*H2O
H2SO4
H2S2O7
SO3
Note that customarily with evidence, it is H2SO4*2H2O, not H6SO6, yet
H2S2O7, not H2SO4*SO3
For system H2O-N2O5, I have seen phase curve between H2O and HNO3, but not the part between
HNO3 and N2O5.
Are there any solid phases in system H2O-SO3-N2O5 that you would write as several molecules not including
water?
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j_sum1
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Quote: Originally posted by DraconicAcid  |
Some are, some aren't. Even in some coordination compounds, some of the water is coordinated to the transition metal centre, while other water
molecules are simply stuck in the lattice. |
That was kind of my point. Some.
I remember being informed by woelen that it was possible (common) to produce crystals of complexes. I had previously only associated complex ions
with solutions, and while I was aware of hydrates, I did not associate them with any kind of complexing.
And of course, the situation is even more complex than that (pun intended). The water or other solvent may be complexed or it may simply be trapped
in defined stoichiometric ratios in the interstices of the crystal lattice.
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unionised
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Does H3O+ HSO4- count?
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