If an ice cube was placed in liquid nitrogen and then put in a glass of water?

Question

Would the water freeze or the icecube melt? Asume a normal size glass and cube

Paul B you are wrong An ice cube can be just blow freezing and putting it in liquid nitrogen takes it down to 77deg K! I supose you think a bit of iron is the same when red hot and room temparature. Pick it up and tell me!

Answer 1

The latent heat of fusion of ice is 80 calories per gram. One gram of ice, cooled by the liquid nitrogen to approximately -200 degrees centigrade (it is not quite that low but nearly so) would freeze 2.5 grams of water already at zero centigrade, while itself warming to that temperature.

Assuming, as the questioner says to do, a normal size glass and piece of ice, there would be more than two and a half times as much water as ice, so none of the water would freeze if it was stirred. In practice, some water would probably freeze round the ice for a while.

If heat was conserved, and there was *less* than two and a half times as much water as ice, all the water would freeze. But this condition is excluded by the questioner.

Answer 2

Paul B not correct. The ice cube's temperature would drop to that of the liquid nitrogen. Depending on how you did it, the thermal shock of that might splinter the ice cube, but ice it would remain, at minus a buzzilion degrees. take it out of the N2 and drop it in the water; a large amount of that water would freeze as the ice cube sucked heat in from the water and its own temperature rose - until both it and the water were at freezing (thawing) point, at which point equilibrium is reached and the action stops, with some ice and some water, or if there's not a lot of water to start with, all of it would freeze and end up at some temperature less than zero.

Answer 3

if ice cube had been in N2 for long enough it would be a very cold ice cube when taken out of N2 (close to temperature of liquid nitrogen)
when carefully placed into water a bit above freezing point the heat in the water would flow into the ice block which becomes warmer but would probably remain solid depending on masses.
latent heat of water would be relevant

Answer 4

It depends on the proportion water/ice and the temperature of the water and ice before you put the ice in. I'm not gonna do this now, but you must calculate the amount of latent heat in the ice-cube compared to the amount at freezing point (0 Centigrade), and the amount of latent heat in the water compared to that at freezing point. The one with the largest number will determine the final state of the water.

Answer 5

Of course you can make an ice cube colder, it just won't change shape. In this case, the ice cube would melt because even with no energy in it, such a small cube wouldn't be able to take down the 'average' energy of a glass of water per unit volume sufficiently. but the water would get colder.

Answer 6

Ice cube - less than or equal to 0 degrees Celsius.
liquid Nitrogen - less than or equal to -197 degrees Celsius.
Water - more than or equal to 0 degrees Celsius.

I assume that the ice cube must be as cold as the liquid N2 for it to exist. So my conclusion is that the water must freeze.

Answer 7

Without knowing the precise volume of the glass and ice cube,
I cannot do the math, but I would say the obvious effect would be the glass would shatter due to the rapid stresses of cooling.

Answer 8

er, teh ice cube is at 0c, liquid Nitrogen is a bit colder, so much so, the ice cube will boil off some of the nitrogen before it freezes... and absorb it into the ice..when you drop it into room temp water, the ice cube will boil vigorously and dissapear, or the heat differential wil crack the class.

Answer 9

You can't make an ice-cube any colder than it allready is so nothing would happen to the ice cube when it was put in the liquid nitrogen, then it would melt normally when you put it in the glass of water

Answer 10

The ice will float, and a fog will develop. Let's just make some ice cream, or a Slurpee from the concoction.