If U put an ice cube in water, how come the melted ice doesn't increase the volume of the water?

Question

IF THAT WAS CONFUSING, LET ME EXPLAIN IT ANOTHER WAY.
when u drop an ice cube in a glass of water, of course, after a while the ice cube will melt. (ice cube is frozen water)

but the dissepiated water does not increase the volume of the water already in the glass

can anyone explain why not?
thanks

Answer 1

The ice and the water are both made of the same substance, the ice is just in a less dense form. So all the volume it is displacing is equal to its own weight (this is the standard principle of buoyancy), and when it melts its own weight turns into more water, which still displaces as much as its own weight. In other words, it is already displacing as much as it contains, so when it melts the level of the water does not change (but the amount of ice sticking above the water does; it goes down).

However, with most other liquids, this does not happen. This is because most substances are less dense when liquid than when solid; water is more dense because the solid form is a crystal which arranges its molecules to take up extra space (most solids don't arrange their molecules this way, and thus are not crystals). So if you dropped a lump of gold into a pot of melted gold, for example, the level would actually go up as the solid stuff melted (especially if heat was constantly being applied). Similarly, if you held your ice cube under the surface of the water somehow, the level of water in the glass would shrink as the ice melted. The real key here is the fact that the ice floats not only at the surface, but partly ABOVE the surface of the water.

Answer 2

Easy:

Ever put ice in an ice-cube tray and freeze it, only to find that it has gone over the top of the tray? Water expands when frozen.

SO....when you throw in an ice cube and look at the volume of water, it has gone up slightly because some of the ice cube is displacing water, making it higher.

THEN....when it has melted it actually takes up less room than it did when frozen.

Your question is a little tough to understand though.... Are you suggesting that a cup of water vs. a cup of water with an ice cube in it (both started with the same amount of water) will be the same? Thats not true.

To test the this, get A BUNCH of ice cubes, and add them to a half cup of water. Watch once they've melted. There will be more water than just a half in the glass.

One thing that can screw up results in this situation is sublimation, when some of the water in the glass goes off into the air as vapour (same as sweat leaves your skin in the wind)
So do the experiment in a place where there is not alot of wind/air movement.

GOOD LUCK!

Answer 3

Because you are only measuring the volume of the water that is ALREADY in the glass...you are not measuring the volume of the ice cube and adding it to the total sum of the actual water in the glass. It like comparing apples and oranges. One is a liquid - one is a solid.

Once the ice cube melts then obviously the volume of the liquid (water) will increase. That is, of course, depending on how long the glass of water has set out...hence evaporation.

Answer 4

Really? Because the icecube takes up as much volume when it is frozen as when it is melted. When you drop it in the glass of water frozen it will increase the volume in the glass. When it melts the ice cube itself doesn't increase in volume and either will the water.

Answer 5

Ever see the little air bubbles in an ice cube? The way that crystals form when water is frozen actually decreases the density of the water. The level of water in your glass will actually go down once all the ice cubes have melted.

Answer 6

When you put the ice cube in the water it displaces some of the water. As it melts, it is no longer taking up that space. There is technically more liquid water in the cup, but the level looks like it hasn't changed because the ice displaces the same amount of water that makes it up.

Answer 7

The ice cube is water. Just because it melts does not mean there is any extra water in the glass. The water from the ice cube was already taking up space when it was in ice form. And dissipated means disappeared, not melted.

Answer 8

What's dissepiated water? Increase the volume of water from what?

If you had 1 cup of water and you dropped an icecube in it, the volume would increase by, lets say, 1 tablespoon. However, when the ice melts, the water volume will go down, because water expands when it freezes. But you will still have more water in the cup than when you started out.....unless you let it sit there and evaporate for awhile!

Answer 9

Water has a unique characteristic over other fluids. Its the only fluid that expands when heated (boiling) OR cooled (frozen). The volume of the ice in the drink will displace its it own size, but as it melts it will not increase the overall volume of the fluid because its temperature it falling and thus the its "size" is decreasing ( but not by enough to really notice)

Answer 10

When you drop the ice in the glass, it does increase the volume. When it melts, there is still the same amount of water as the cube.. Even though water expands when it freezes, it still has the same volume......