D for Dry ice

This is the fourth in the series of 26 posts this month, one post a day, barring four Sundays, each on a theme corresponding to a letter of the English alphabet. The theme this year is "Chemicals in our life", spurred by my interest in chemistry.

Dry ice is not ice. It's actually carbon dioxide, or CO2, the gas that we exhale when we breathe. 

The carbon dioxide we always know is a gas. But dry ice is nothing but carbon dioxide in solid form.

Why it's called so is not quite clear. Apparently, it's called so because, when heated, it does not melt into liquid (like normal ice) but instead becomes gas, skipping the liquid phase.

The process wherein a solid substance, on heating, transforms directly into gas is called sublime or sublimate.

Dry ice is very cold, about -78°C (-109°F), and can cause frostbite if handled without proper protection. 

We get dry ice by increasing the pressure and decreasing the temperature of gaseous CO2.

This process brings the CO2 molecules together. Thus it becomes solid. 

In a solid, the molecules are closer; in a liquid, they are slightly distanced; and in a gas, the molecules are still farther apart.

In other words, dry ice is made up of CO2 particles, which are tightly packed and form a crystalline structure.

Dry ice, because of its very low temperature, is primarily used for cooling. 

Some of the uses of dry ice are: 

- Food preservation: Dry ice can keep food frozen for longer than regular ice, and prevent bacterial growth. It is often used to transport perishable items such as meat, seafood, ice cream, etc.

- Medical applications: Dry ice can be used to freeze and remove warts, moles, and other skin lesions. It can also be used to preserve organs, blood, and tissue samples for transplantation or research.

- Entertainment: Dry ice can create a spooky atmosphere for Halloween parties, haunted houses, or theatrical performances. It can also be used to make smoke effects for music concerts, magic shows, or science experiments.

- Cleaning: Dry ice can be used to blast away dirt, grease, or paint, from surfaces. This process is called dry ice blasting or CO2 blasting, and it is more environmentally friendly than using other chemicals or water.

Dry ice is hazardous; besides causing skin damage and eye irritation, it can get converted back to gaseous CO2. And in poorly ventilated rooms, it can be dangerous.

Images from Pixabay

The information provided in this post has been obtained from multiple, authentic resources. However, it is presented in an abridged format and might not have all the details. Therefore, before acting on any information, readers are requested to exercise caution and do further research.

This post is a part of #BlogchatterA2Z 2023. I am also on A2Z April Challenge.