If an unopened bottle of water freezes, and then thaws... is there more water in it? or what would be the exact result on the original mass of water.

If a 16 ounce bottle of water froze, then thawed you'd still have 16 ounces of water.

Same

Water is unlike other substances since it expands when it freezes, but there's still the same amount of it before, during, and after freezing.

There will be less right after it thaws.....

Freeze, expand, crack, thaw, leak, swear.

I think as it freezes and loses energy it will lose a tiny bit of mass due to mass-energy equivalence, then regain it again when it thaws. However this would be too small to be measured.

Frozen Water More Volume, Same Mass

Unfrozen Same Volume, Same Mass

Like everyone else said, you'd have the same amount.

SO water hacks?

You nailed it.

But what happens essentially is that due to waters shape when it links up with other molecules there are large holes inbetween leaving a lot of empty space.

water sure is crazy

Not really. Considering the scientific principle that matter cannot be created nor destroyed, water would be more of a "hacker" if it could actually, spontaneously increase in substance. When water freezes, air expansion causes the entire substance to increase in volume. When it melts, the air reduces in volume and returns the water's volume to its original size.

Is this a serious question? Where would the extra water have come from? Pixies?

It's not really air expansion, Wombat has the right answer. Water molecules are like little magnets shaped like ^ that can click together. It's not magnetism but electrostatic force, but it's like magnetism. This gives water lots of its properties like surface tension (and formation of droplets and bubbles) and a high boiling point. When you reduce the energy in the water, it's easier for the little magnets to form into a regular lattice, which takes up more space. This is my vague understanding anyway.

I have often though of marketting a plain envelope marked:

"ACME Instant Water"

with instructions on the back that state:

"Add contents to 8 ounces of ordinary water - makes 1 cup"

~ I bet people would buy it....

http://en.wikipedia.org/wiki/Neck_(water_spirit)