How to make Dry ice?

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 image of Dry ice, with fumes coming out of Halloween Pumpkin

Wouldn’t it be fun if we make Dry ice for a party and create special effects like fog? Yes it is!! In many horror movies, they use dry ice for creating the artificial fog. Dry ice is solid carbon-di-oxide (chemical symbol CO2). Carbon-di-oxide is the gas that plants use in photosynthesis process. Dry ice was observed initially by a French chemist Charles Thilorer in the year 1834. It is a white substance which is formed when carbon-di-oxide is cooled and compressed. Dry ice is used to maintain  the product in the frozen state. Dry ice has more cooling energy than the regular ice.


 What are the Physical and chemical properties of Dry ice?

Dry ice changes directly from solid to gas at -78.5 degree centigrade at normal atmospheric pressure without changing to a liquid state. Dry ice is colorless, odorless, non-flammable and slightly acidic. The chemical formula of dry ice is CO2. It has two oxygen atoms and one carbon atom. The density of dry ice ranges between 1. 4 to 1.6 gm/cm cube. Dry ice is low in heat and electric conductivity. This is due to the inter molecular Van der Waals forces present between them. Dry ice is also non-polar. It has a dipole moment of zero. Other name of dry ice is card ice.


What are the materials needed to make Dry ice? 

We can make dry ice at home for keeping things cold or for beautification. Dry ice is easy to make, but proper precautions should be taken before starting to make it. Dry ice is hazardous if touched by uncovered skin. We have to keep the area that contains dry ice well ventilated. This is because the concentration of carbon-di-oxide increases, as dry ice vaporizes as fumes, if proper ventilation is not there which intern can make it toxic / harmful. The things that are needed for making dry ice in a smaller quantity are as follows: 

  • Protective gloves
  • Protective jacket 
  • Small Carbon-di-oxide tank
  • Tongs
  • Jar with no lid
  • Duct tape
  • Ice bag


What are the steps involved in the preparation of Dry ice?

  1.  Wear protective gloves and a protective jacket (if needed),  as dry ice when touched without gloves can burn the skin
  2.  Cover the nozzle of the carbon-di-oxide tank with the ice bag firmly, so that the ice bag is attached to the nozzle properly
  3.  After making sure that the ice bag is attached appropriately to the tank, open the nozzle of the carbon-di-oxide tank and release the gas for about 20 seconds or more depending upon the amount of dry ice needed. This should result in the formation of dry ice
  4.  Turn off the nozzle of the carbon-di-oxide tank
  5.  Slowly remove the ice bag and shift the dry ice to the jar.
  6.  Never close the jar with a lid, because the pressure that comes from the dry ice will blow apart the jar
  7.  Repeat the process if more dry ice is needed.


What are the uses of dry ice?

Dry ice is predominantly used in food industry to preserve food items from bacteria and for making a sparkling drink like root beer. It is also used to freeze fruits so that it won’t become soggy when thawed. It is used to preserve biological samples also. It  is used for creating the fog like effect in movies. It  is used in Blast cleaning for removing residues from the industrial equipment and also food processing equipment.


What are the disadvantages for Dry ice?

Temperature related injury is an ever present hazard with dry ice. So always handle it with care, wearing gloves. Carbon-di-oxide, which will be the result of the evaporated dry ice, can create asphyxiation hazard, especially in places without proper ventilation. As CO2 is heavier than surrounding air, it will settle at lower levels of the rooms, posing danger to children

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