STATES of MATTER Dry Ice
STATES OF MATTER – “Dry Ice”
What is dry ice?
Dry ice is frozen carbon dioxide. Ablock of dry ice has a surface temperature of -109.3 degrees Fahrenheit. Dry ice also has the very nice feature of sublimation. As it breaks down, it turns directly into carbon dioxide gas rather than a liquid.
How is dry ice made?
Dry ice is easily manufactured. First, gases with a high concentration of carbon dioxide are produced. Second, the carbon dioxide-rich gas is pressurized and refrigerated until it liquefies. Next, the pressure is reduced. When this occurs some of the liquid carbon dioxide vaporizes, causing a rapid lowering of temperature of the remaining liquid. AS a result, the extreme cold causes the liquid to solidify into a snow-like consistency. Finally, the snow like solid carbon dioxide is compressed into either small pellets or larger blocks of dry ice.
Why does dry ice create bubbles and gas when dropped into water?
When dry ice is dropped in water, it creates tiny carbon dioxide bubbles. These CO2 bubbles are very cold. As these CO2 bubbles make their way to the top of the water and mix with the air, something fun happens. The cold CO2 bubbles, made from the dry ice, cause a sudden drop in temperature. This drop in temperature causes tiny droplets of water in the surrounding air top form a visible fog. Because the fog created is a mixture of water, air, and CO2, the gas is denser than the air we breathe. This causes the fog to drop low to the ground.
Why did the tongs (metal) make a sound when pressed against the dry ice?
The warm tongs will cause the dry ice to sublimate where it is being held. The sublimating gas directly underneath the tongs will lift the tongs off the ice, but the pressure of you holding the tong handles will push the tongs back against the dry ice. This repeats so quickly that the tongs vibrate, generating a singing sound that will vary with the pressure that you exert on the handles.
What made the stopper fly off the test tube that contained water and dry ice?
As the dry ice inside the test tube sublimates, more and more carbon dioxide gas builds up. This increase in pressure eventually causes the stopper to blow off.
Why does dry ice slide across the table so easily?
The dry ice pellet sublimates faster on the bottom where the pellet is touching the warm table top. Carbon dioxide gas pushes down against the table, lifting the pellet up and decreasing friction between the pellet and the table. The pellet rides on a thin layer of carbon dioxide gas across the table.