toxin
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Henry's Law
How would you go about answering this question ?
The largest value of the Henry's Law constant for the liquid solvent H2O will be obtained with __________ gas as the solute and a temperature of
__________°C.
a.C2H4, 45
b.Ar, 11
c.HCl, 49
d.CO2, 32
e. N2, 15
All I know is that with the stronger the attractions between solute and solvent molecules, the greater the solubility, and attractive forces increase
with increasing size and mass.
[Edited on 9-2-2006 by toxin]
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guy
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Well the largest constant will be for the nonpolar at high temps because Higher temp = low solubility for gases.
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toxin
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Henry's Law says that the Solubility of a gas = constant * (Pressure above gas solution)
My book says that ionic and polar solutes are more likely to be soluble in polar solvents; thus HCl being the only polar molecule shown, wouldn't it
have the greatest solubility considering water molecules are also polar and hence have the largest henry's law constant ?
*Solubility of HCl in water at 20 °C is 72 g/100 ml
[Edited on 12-2-2006 by toxin]
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guy
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Hmmm. I have two chemistry books that say different things so now Im confused.
From CHEMISTRY by Zumdahl
P = kC (P=partial pressure of gaseous solute, k=constant, C = molarity)
From Chemistry and chemical reactivity by Kotz and Purcell
Molality = kP (P=partial pressure of gaseous solute, k=constant)
[Edited on 2/12/2006 by guy]
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unionised
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IIRC HCl doesn't really have a "Henry's law constant" (whichever way you do the division).
Because HCl disociates in solution p(HCL) as roughly proportional to the square of the concentration in solution.
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toxin
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In that case if HCl did have a Henry's law constant, wouldn't it be greater than that of CO2's ?
Im really confused with this because non-polar CO2 must be insoluble in water however it probably reacts with water like this CO2(g) + H2O(l) ---->
H2CO3(aq) forming carbonic acid which of course is soluble in water.
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toxin
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Turned out to be HCl at 49 °C, I must have been in luck !
makes scence because HCl was the only polar molecule.
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