How to Make Dry Ice
Dry ice or more commonly known as dry ice is a frozen carbon dioxide (CO2) compound. Dry ice is usually used as a coolant in places where there is no refrigeration machine.
Dry ice has a lower temperature than water-based ice, so dry ice can cause chills when touched directly with the skin. It has a low temperature of -78.5 ° C (−109.3 ° F) at atmospheric pressure and is relatively easy to manufacture.
Carbon dioxide is a gas released as a result of respiration and various combustion of hydrocarbons. Apart from being at a lower temperature than ice made from water, dry ice doesn't leave any residue.
Dry ice is generally a harmless compound but in high concentrations it can cause asphyxiation due to lack of oxygen. Dry ice is also dangerous to handle without safety as it will cause chills (frostbite).
With the right equipment and materials, dry ice can be made at home as long as it's done with the right precautions.
The person who first discovered dry ice or dry ice was a French chemist named Charles Thilorier, in 1835. The dry ice was discovered when he opened a container filled with carbon dioxide that had been pressurized.
Dry ice can be made from a fire extinguisher that contains CO2 or carbon dioxide. This causes dry ice to hold up to 10 times as much oxygen as if it is placed in an airtight space.
Dry ice has a density between 1.2 and 1.6 kg / dm3. Dry ice does not contain harmful carbon dioxide. However, the dry ice binds to oxygen and fills it with carbon dioxide, which causes a person to become short of breath due to lack of oxygen.
Dry ice or dry ice if it is placed or mixed with water, the smoke will come out. this is often used by a stage stylist in decorating and adding property and effects to an art stage or concert.
In addition, dry ice is also used as a substitute for ice cubes in ice cream shipments to maintain its freezing point. In medical terms, dry ice is used for the need for temperature stabilizers for drugs, both for storage and for shipping, in medical terms it also measures the temperature of dry ice using a data logger.
How to Make Dry Ice
If you want to make dry ice yourself at home, here are the steps for making dry ice:
Tools and Materials for making dry ice are needed:
- Carbon dioxide tank or CO2-filled fire extinguisher (APAR)
- Gloves,
- Pillow case,
- Protective glasses,
- Container (jar / bowl / plastic ice bag)
- duct tape / strong adhesive.
How to Make Dry Ice:
- Place the pillowcase tightly over the faucet mouth of the liquid carbon dioxide tank.
- Then open the lid on the faucet. Do not let any gas escape except towards the cloth. If you are worried that the pillowcase will fly off, use duct tape to secure the joints.
- Spray for 2 - 3 seconds.
- Then, the ice will immediately collect at the bottom of the pillowcase.
- When the liquefied gas that is released condenses on the fabric, the carbon dioxide will evaporate and dry ice forms.
- Then carefully remove the pillowcase and you should see a small pile of dry ice at the bottom of the pillowcase. It will resemble white stryrofoam crumbs.
- Do not hold dry ice for too long as it can injure your fingers even if they are protected by gloves.
- Next, transfer the dry ice to a safe and practical container, such as a bowl, strong plastic ice bag, or thermos. Do not store in soft ceramic or glass containers as the cold temperature of dry ice can cause them to shrink and break.
This method is for making only a small amount of dry ice. To produce large quantities of dry ice, evaporative cooling is required. Therefore, if you want dry ice in large quantities, you should just buy it from a retail seller or buy a dry ice making machine which can cost up to several thousands of dollars.
Dry ice is usually stored in insulated containers because when exposed to air, it immediately releases carbon dioxide gas. Because the temperature difference between dry ice and the environment is quite large, the phase change occurs directly from solid to gas, without going through the liquid phase.
Physical properties of dry ice.
The following are some of the properties of Dry Ice according to Physical and Chemical properties:
- Has a white color resembling snow.
- Acidic in nature.
- Specific gravity = 1.56.
- Melting point = -109.6 0F
- Critical combat = 88,430
- Critical pressure = 1077 lb / in abs.
- Latent heat of vaporation = 158.6 btu
- Latent heat of fusion = 82 btu
- Liquid density = 0.117 lb / cuft.
- Solid density = 90lb / cuft.
- Latent heat of sublimition = 248 Btu.
- Refrigeration effect = 275 Btu / lb
Dry Ice Chemical Properties.
- Difficulty dissolving under ordinary conditions.
- It dissolves in water to form H²CO³ which is a weak acid which is unstable and can decompose into CO² (carbon dioxide) and water again.
- At elevated temperatures (over 1200 ° F) carbon dioxide dissociates (2 CO² → 2CO + O²).
- Dissociation conversion.
- At 1340 ° F it is 25 x 106%.
- At 3146 ° F it is 2.1%.
- With a carbonate solution it becomes bicarbonate.
