Why doesn;t a drink overflow when the ice melts?

Question

I've wondered for ages. When you fill a glass to the top with drink and ice cubes, why doesn't the glass overflow when the ice melts? base this answer on the fact that when a solid melts to a liquid the molecules in the substance move further apart and take up a greater volume. ?!

Answer 1

Water ice actually occupies a larger volume than liquid water. This is why water pipes burst when they freeze - the water expands as it freezes and bursts the pipe.

This means that as the ice melts in a drink the total volume gets smaller so it is actually LESS likely to overflow.

Answer 2

You are right to say that generally, as a substance melts, it takes up a greater volume BUT water is the only exception to this rule (that I know of). Water actually gets larger as it freezes and continues to increase in volume until -4degreesC when it acts like a normal chemical and contracts the colder it is.

Also, if you put ice cubes in a glass of water, you will notice that some of the ice is in the water and some is outside. This means that the glass is not actually filled with liquid water but rather liquid water and some ice. The mass of the water displaced by the ice is equal to mass of the ice (Archimedes found this out) and so as the ice melts, the water level stays the same.

The surface tension of the water (the skin) also lets there be slightly more water held in the glass than the glass's capacity is.

Hope this explained it!!

Answer 3

Water has a greater volume than ice so when ice melts the volume actually goes down. This is because ice has a highly ordered structure with specific distances between the molecules where as in water the molecules can pack in more closely together.

Answer 4

If ice were more dense than water then the ice would not float. It would sink and only displace its own volume of water. In this case were the ice to melt its volume would increase and the glass would overflow

However ice floats. This means that it is less dense than water and therefore only displaces a quantity of water equivalent to its own mass.

A glass full of just water will therefore weigh the same as a glass full of a mixture of water and ice. The amount of ice you see above the surface of the water is simply the amount by which the water expanded when it became ice. When the ice melts the water therefore does not rise.

By the same principal, were the ice at the north pole melt sea levels would not rise as the ice at the northpole floats on the surface of the sea.

However the ice at the Southpole is on land (the continent of Antartica) If this were to melt then sea levels would rise.

Answer 5

When you fill an ice cube tray to the top and let it freeze, the ice cubes are taller than the top when they are frozen. This is because water, like most things, expands when it gets cold. As the ice melts in your glass (thereby getting LESS cold) the ice contracts again to the original level of the water, and the liquid in the glass is getting less cold as well as it seeks room temperature and there is less ice to keep it chilled.
In other words, a glass of room temperature liquid takes less space than a glass of cold liquid and ice.

Answer 6

Water expands when frozen. Look at an ice cube tray. The cubes expand over the tops of the compartments. Hence, the mass of ice cubes would be more than the mass of plain water. So, my answer would be that there is less mass when the ice melts.

I'm not an expert, just a layperson, so I don't know how accurate this is but, it seems to make sense.

Answer 7

ice takes up more volume than water - as it crystallises it e x p a n d s - this is why ice and glaciers are a powerful natural force, capable of gouging out valleys over time. So put your glass of water in a freezer and it will probably shatter. It's likely the greater part of the ice in your glass is under the 'waterline' (mini-iceburgs) and so when it melts it contracts. The amount of 'meltwater' won't exceed the volume of ice above the glass rim. As an aside, if you put a joint of uncovered meat in a freezer at say -18 degrees C it will freeze and at some point lose surface moisture to the surrounding atmosphere - so, the weight of the joint is affected (the drying effect is known as freezer-burn). 'Cold air' is heavier than warm air, and so
the net effect on the joint of meat is determined by a number of factors, including it's position inside the freezer.

Answer 8

Because while ice comes from water, water it made up of mostly oxygen, H2O, water is one part hydrogen two parts oxygen, both are gases and only when put together do they form a solid, water. Thus when ice melts it reverts to it's natural gas form and evaporates into the air, so no longer a solid it doesn't cause the glass the overflow.

Answer 9

That's like which weighs more a pound of feathers or a pound of lead! The glass will hold what it will, yes ice spreads out after it melts, but when it turns into a liquid it fills in all the gaps of air that was between the cubes.

Answer 10

Because when you put the ice in, you already dispersed the same amount of liquid...it's just that the water in the ice is more dense. When ice melts, the level may even drop because the water molecules will contract, and the air bubbles in the ice will release as it melts.