Re: Why does sugar disolve in water? What is happening to the molecules?

Hi Cullen.
it's a question that I remember having once.  

Imagine that the sugar is matter (see the dictionary for a definition) 
which has mass.  That is, sugar particles have a real size and "weight" 
(mass and weight have different formal definitions, which I leave to you 
to explore).  Water is the same way, but you can't see the 
water "particles" wit your eyes.

Now, Imagine a swimming pool full of basketballs (the sugar particles).  
If you dumped truckload after truckload of bb's, marbles, etc into the 
swimming pool, it would appear as though you haven't increased the overall 
volume of the system.  What you've done is fill the interstitial (in-
between) spaces between basketballs.  At some point, though you'll 
overflow the pool with bb's, marbles, etc.  

the same thing happens with a glass full of sugar.  You keep adding water 
to it, and it seems to disappear into the sugar until you dissolve it 
all.  If you were to take two of the same glasses and fill one with sugar, 
then filling each with water, you'd find that you added less water to that 
glass with the sugar.  

So, mass doesn't really disappear.  It's really there.  If you leave the 
glass our for a while, the water will evaporate and the sugar will be left 
behind (it will seem like less, because it will recrystallize into a 
tightly packed structure).

Please feel free to email me at weibelm@battelle.org if you have further 
questions.

Best Regards,
Mike