They are soluble in non-polar solvents because van der waal's forces form between the simple structure & the solvent, which allows a solution to form.
But are they soluble in polar solvents?
If not, why not, if yes, why?
cheers
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Another question about solubility:
In our experiments last week, we did the solubility of different compounds in an organic solvent, as well as in water, but we didn't go over this when we did our table today. Do we have to add what we found?
In answer to Lewis' original post, let me ask you which of these simple molecular compounds you think WOULD be soluble in water:
Glucose (C6H12O6)
Iodine (I2)
Hydrogen chloride (HCl)
Ammonia (NH3)
Methane (CH4)
Sulphur dioxide (SO2)
In each case, can you explain WHY/WHY NOT?
In terms of solubility in water v. solubility in organic solvent, Vicky...
When something dissolves in a solvent, it has to overcome the forces of attraction (hydrogen bonds) between the water molecules. This requires a significant amount of energy. Energy is then given out when new intermolecular forces are set up between the substance and the water molecules. If the energy needed to overcome the hydrogen bonds is similar to that given out when the new intermolecular forces are set up, the substance WILL be soluble in water - this is likely to be the case if the new intermolecular forces are also hydrogen bonds.
Most organic solvents contain molecules that are held together by Van der Waal's forces. Can you explain why simple molecular substances that are not soluble in water might be soluble in organic solvents?
You might find this page on the chemguide website useful. (You could also use the links to further improve your understanding of intermolecular forces.)
www.chemguide.co.uk/atoms/structures/molecular.html
i don't think any of them are soluble in water as they are all covalent structures I think. simple molecular structures are only soluble in non polar solvents, whilst water is polar, and giant covalents are not solbule in either polar or non polar. . .
You're right that, as a general rule, simple molecular substances do not tend to be soluble in water.
However, if the substance can form hydrogen bonds to water, i.e. if it contains a slightly positive H and/or a slightly negative N, O or F, it WILL be soluble in water.
Which of the substances in my previous post do fit into that category and therefore would be soluble in water?
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