Solvation is an everyday process, one most people don't give much thought. Sugar dissolves in tea, oil-based paints in turpentine, nail polish in acetone. It's also well known that certain substances, like oil, will not dissolve in other substances, like water.

While it seems intuitive that solutes (like salt or sugar) dissolve best in fluid solvents (like water), whether a solute and a solvent are compatible depends on their polarity, that is, how charges are distributed within a molecule. If there is an uneven distribution of positive and negative charges the molecule is polar. Polar solutes will dissolve in polar solvents; hence, sugar will easily dissolve in water, because both substances have some negative and some positive atoms, but because oil is non-polar, consisting of nearly neutral atoms, it will not dissolve sugar.

Solvation is involved in the vast majority of chemical reactions; however, this important process is not entirely understood. "A lot of what's important in chemistry is understanding why a reaction happens in a particular way…or why you mix two things together, A and B, and get C, but not D, when D is a perfectly viable option," says Brent Krueger, an assistant professor of chemistry at Hope College in Holland, Michigan. "The way solvation happens, and the way solvent affects a chemical reaction, are really the same thing, so if we can understand one of them, we can understand the other in detail."

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Access Online | Posted 12-14-2004