Dry ice, sometimes referred to as "Cardice" or as "card ice" (chiefly British English), is the solid form of carbon dioxide. It is used primarily as a cooling agent. Its advantages include lower temperature than that of water ice and not leaving any residue (other than incidental frost from moisture in the atmosphere). It is useful for preserving frozen foods, ice cream, etc., where mechanical cooling is unavailable.
Dry ice sublimates at -78.5 °C (-109.3 °F) at atmospheric pressure. This extreme cold makes the solid dangerous to handle without protection due to burns caused by freezing (frostbite). While generally not very toxic, the outgassing from it can cause hypercapnia due to buildup in confined locations.
1._¿Manufacture?Dry ice is easily manufactured.First, gases with a high concentration of carbon dioxide are produced. Such gases can be a byproduct of another process, such as producing ammonia from nitrogen and natural gas, or large-scale fermentation. Second, the carbon dioxide-rich gas is pressurized and refrigerated until it liquifies. Next, the pressure is reduced. When this occurs some 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.
2._¿HISTORY?It is generally accepted that dry ice was first observed in 1834 by French chemist Charles Thilorier, who published the first account of the substance.In his experiments, he noted that when opening the lid of a large cylinder containing liquid carbon dioxide, most of the liquid CO2 quickly evaporated. This left only solid dry ice in the container.In 1924, Thomas B. Slate applied for a US patent to sell dry ice commercially. Subsequently, he became the first to make dry ice successful as an industry. In 1925, this solid form of CO2 was trademarked by the DryIce Corporation of America as "Dry ice", thus leading to its common name. That same year the DryIce Co. sold the substance commercially for the first time; marketing it for refrigerating purposes
2._¿Applications?Commercial The most common use of dry ice is to preserve food, using non-cyclic refrigeration. It is frequently used to package items that need to remain cold or frozen, such as ice cream or biological samples, without the use of mechanical cooling. Dry ice can be used to flash freeze food or laboratory biological samples, carbonate beverages, and make ice cream. Dry ice can be used to arrest and prevent insect activity in closed containers of grains and grain products, as it displaces oxygen, but does not alter the taste or quality of such foods. For the same reason, it can prevent or retard food oils and fats from becoming rancid.
- Water or soda bottle .
- Dry ice .
- Ice Pick or Hammer.
Instructions:1:Cut a hole in the bottom of the box large enough to fit your bottle into it in a standing position. Place the box with the hole on top in your launch area. 2:Drill a small hole in the center of the bottle cap. Cover the hole with a piece of clear tape. 3:Fill the bottle 1/3 full with water. 4 :Use the icepick or hammer to break up the block of dry ice. Wear gloves when handling the ice. Place enough dry ice into the bottle to finish filling the bottle to the half way mark. 5 :Screw the lid tightly on the bottle and place it upside down in the launch pad. Quickly move away and watch from a safe distance. 6 :Pressure will build in the bottle until it pushes through the tape to vent. This will cause the bottle to rocket into the sky. Dry ice rockets are unpredictable, so the rocket might also move horizontally.ESPAÑOL pagina inicial