What is "dry ice"? How is it made?

Question

Note for folks clicking here to read these great answers: Sublimation is the strange thing that will happen to the ice you didn't scrape off your windshield, that just 'goes away' without melting...

Thank you for the great answers, everyone!

Answer 1

Dry ice is produced by compressing carbon dioxide gas to a liquid form, removing the heat produced by the compression and then letting the liquid carbon dioxide expand quickly. This expansion causes a drop in temperature so that some of the CO2 freezes into "snow", which is then compressed into pellets or blocks.

Answer 2

As other answers have noted, dry ice is carbon dioxide in the solid phase.

However, it is interesting to note that unlike water, carbon dioxide cannot exist in the liquid phase at atmospheric pressures at any temperature. Instead, it "sublimates" - that is, passes directly from solid to gas without becoming a liquid. That is why it is "dry."

The easiest way to produce the dry ice is to convert CO2 gas into liquid at extremely high pressure - where the liquid phase can co-exist with the gas. Then, if the liquid is released into a lower pressure environment, it will solidify as CO2 crystals.

Answer 3

Dry Ice is the common name for solid carbon dioxide. Carbon dioxide gas is cooled to below -78°C, at which point the gas condenses and solidifies.

Answer 4

dry ice is the other name of solid CO2 (carbon dioxide)

Answer 5

It's solid carbon dioxide, think it freezes at around -88°C or thereabouts.

Answer 6

dry ice is carbon dioxide solid. it is carbon dioxide gas that is compressed until it becomes a solid

Answer 7

dry ice is frozen CO_2

Answer 8

they made it by carbon monoxide and it use for made coll endearment.....