Home > Community > Why are covalent compounds insoluble in polar solvents although they have a weak molecular force of attraction?
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Melinda Siebold

Why are covalent compounds insoluble in polar solvents although they have a weak molecular force of attraction?

Donald Werve  Follow

Like dissolves like. The problem is that the polar solvent particles stick together and there is very little tendency to interact with the non polar solute particles.

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D. Sigdel  Follow

Water is a polar solvent and it dissolves other polar compounds very well.

Hexane is a non-polar solvent and it dissolves other non-polar compounds.

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Bill Starmann  Follow

I’ll give you 3 for the price of one:

hexane, benzene and tetrachloromethane.

Three very different non-polar solvents for different covalent compounds.

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Chris Beulah  Follow

Because your position that covalent compounds are insoluble in water is false. Water itself is a covalent compound. Solubility depends on a molecule’s polarity, not what type of intermolecular bonds exist within it.

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Catherine Salierno  Follow

Solubility or insolubility is a matter of relative intermolecular forces between solute and solvent. Some covalent materials are soluble in polar solvents, to a limited extent. Look at paraffin wax, a highly non-polar covalent material, which is soluble in the highly polar chloroform. Vice versa, sodium chloride, a highl polar, indeed ionic, material is soluble in the covalent substance methanol.

Don't forget that polar molecules can induce polarity in non-polar molecules, just by begin near them.

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Daniel Strickland  Follow

Polar solvents act via regions of different partial charge (dipole moments) that are not strong enough to break covalent compounds. In the case of water nonpolar molecules are unable to form hydrogen bonds because they lack regions with partial charges

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Christopher Proescher  Follow

I think you have posed this question incorrectly. Polar solvents, such as water, are charge-separated, and are capable of dissolving ionic solutes by solvating the ion-pair and forming discrete complexes. On the other hand, non-polar solvents are all but incapable of charge separation. Should you pour ethyl alcohol into an aqueous solution of sodium chloride, you will see a fine white mass of sodium chloride precipitate.

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Arthur Macgregor  Follow

Really the issue is with water.

Water is the ridiculously stubborn solvent.

Check out this solvent miscibility table. It tells you which solvents mix with each other and which form two distinct layers. Black boxes are solvents that don't mix:

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