Can anyone explain to me what happens to molecules of NaCl and Sucrose as it's dissolved in disstilled water?

Answer 1

There is a key difference in the way NaCl and sucrose dissolve in water. NaCl is the result of a Na+ ion bound to an Cl- ion. The ions form a very stable crystal lattice structure when in thier pure form, and out of water. Once introduced into water, however, the H2O molecules disrupt the ionic bonds (because water's attraction to the ions is greater than the ions attraction to themselves). The Na+ and Cl- ions are then separated and floating around freely in the water.

Sucrose on the other hand is not an ionic compound. Sucrose represents a glucose and a fructose molecule bound to each other covalently. When introduced into water, sucrose molecules will become separated from other sucrose molecules, but will not be disrupted by the water (ie; its own covalent bonds remain intact).

Answer 2

I saw this on Good Eats. If it's on the Food Network site, Alton Brown described it very well (as usual.)

What you're making is a brine, suitable for soaking meat for juicy cookin' (or a chemistry experiment.) The molecules in the solids dissolve, that is, break into ions, which attach to the ends of the water molecules. I'd have to go look up the chemical structure for the molecules--salt is easy, but sucrose has some carbon and stuff in there. Basically, if you have a molecule, some parts attract positive ions, and some parts attract negative. The molecules of the salt and sugar go attach to the end of the water molecule that attracts each, then the ion breaks off and goes to the other part of the molecule. Does that make sense? This would make more sense with one of those little diagram things with the lines with the chemical bonds and stuff. Sorry I'm a little limited in that respect.

But the usual chemical bonding rules are at work--if one end of the molecule is missing an electron, then the particle that has an extra electron will attach to that part of the molecule. The whole, finishing off the levels in the Bohr model idea, where each level has 2 electrons, then 4, then, um, 8...I think. I need a book. Where's yours?

Hope my non-pictorial, can't remember the chemical formula for sucrose explanation helped. A little.

Answer 3

it goes into solution till it supersaturates at which point it seperates out. the saturation point is dependent on temperature and ambient presssure.

Answer 4

nothing... they don't react...