Like I know it is made from carbon dioxide but what actually makes it so special compared to normal ice? And why is it so dangerous if it is ice?
In: Chemistry
There’s nothing particularly special about it…. it is just a lot colder than ice. Unlike water ice, it ‘melts’ directly back to a gas at normal pressure.
It’s dangerous if you touch it unprotected… it can give you frostbite. If it’s kept in a closed container it can cause an explosion as the gas expands. In a larger closed area it could fill a room with carbon dioxide and cause asphyxiation.
It’s not ice. It’s called dry ice because it’s not wet and looks like ice, it’s not ice. Why is it dangerous? Because it’s CO2. It’ll sublime to CO2 gas in room temperature and if you’re dealing it in a not well ventilated room, you risk losing consciousness.
Dry ice is much colder than conventional water ice, as it sublimes (turns in to gas) at −109.2 °F (−78.5 °C). As the dry ice itself is at a much lower temperature, the items to be cooled can remain at a temperature far lower than freezing. Not only that, the “sublimes” part is also important – when it melts, you don’t get any liquid residue from itself like conventional ice. So there’s no mess to clean up.
On the other hand, the colder temperature also means it can freeze your body part to dangerous levels as well. In other words, you can get a frostbite much more easily. So it has to be handled with care.
CO2 ‘melts’ at a temperature higher than it ‘boils’ (at sea level air pressure). This means that when it would be melting, it doesn’t turn into a liquid but instead into a gas (hence, *dry* ice). This is called “sublimation” (turning to gas) and “deposition” (turning to solid) to make it clear it’s something different than melting/boiling and freezing/condensing.
CO2 sublimates at a *much* lower temperature than ice. If you are used to how cold ice is and apply that knowledge to CO2 ice, then you will be touching something that is dangerously cold. This risks frostbite.
CO2 takes up *much* more volume as a gas than as a solid. This means that if you warm it up in a situation that is sealed with a constant volume (such as in a bottle), the extra volume the gas is trying to take up translates into extra pressure. This extra pressure can explode the container. Exploding high pressure containers vary in exactly how dangerous they are, but they can lead to serious injury pretty easily. (and if the ‘container’ is a person’s body, that’s an ouch)
CO2 is also CO2. As a gas, too much of it in a room will push out all of the O2. [And that’s bad](https://en.wikipedia.org/wiki/Asphyxia).
Edit to add: people use CO2 ice in food/drinks all the time. Anecdotally, you can add it to homemade soda (in a large, unsealed vat) to get a bit of carbonation to it, as well as cooling it down. So it’s not like it’s *dangerous* dangerous; just something to exercise awareness of and moderate caution.
Dry Ice is carbon dioxide. Like straight up carbon dioxide; it’s CO2, cooled down until it condenses into a liquid, then further cooled down until it becomes a solid. CO2 does this at around -109 F. Now it doesn’t *feel like* it’s that cold, because CO2 isn’t exactly great at thermal conductivity.
What makes it “special” is that it’s a gas that is chilled so much; for comparison if you wanted to condense oxygen to liquid and then solid, you’d need to go down to around -361 F.
What can make dry ice dangerous is that it’s literally CO2. You can’t breathe CO2 and your body can’t make use of it, which means in any enclosed spaces, dry ice implies a suffocation risk. It might look neat tossed in a pool for a smoky effect; but hopefully no one goes swimming cuz the next inch or two of space above the pool is going to be nothing but CO2.
There’s nothing really special about it. We call it dry ice because it doesn’t have a liquid state (at normal atmospheric pressure), and it doesn’t add water to whatever you’re trying to keep cool (because it isn’t water).
It’s dangerous because it’s so cold, -80°C. Normal ice just needs to be below 0°C. That will damage your skin much faster than normal ice would. It will also fill a room with carbon dioxide as it sublimates, which will kill you with carbon dioxide poisoning. In a sealed container, it will also expand as it sublimates, resulting in a build up of pressure before it explodes
It’s basically a frozen gas rather than a frozen liquid. It’s much colder than regular water ice which is what makes it dangerous. Handling it without protective equipment can very easily cause severe cold burns and if handling it in a closed space that’s not well ventilated all the carbon dioxide being released as it “melts” then the room gets filled with a lot of carbon dioxide which can basically displace the oxygen and cause hypoxia or even asphyxiation, though that is an extreme case but not impossible to happen.
What makes it special is that it doesn’t actually melt, rather it goes from a solid to a gas through a process known as sublimation. This property makes it particularly useful for things like cooling on equipment or areas where you cannot have water, like electronics. It’s also used for ice blasting for the same reason. Sandblasting is a catch all term for blowing tiny particles of something solid on surfaces to strip/clean them but many materials other than just sand are used, like metal shavings, plastic beads, and dry ice, which essentially leaves no trace afterwards as it turns into a gas, as opposed to every other material which makes a huge mess.
Latest Answers