How long will dry ice last in direct sunlight during summer?

Question

Would mixing about 1\4 of dry ice into about a bucket of ice increase the length of time of how long the ice will stay at a low temperature? Like, say about 7 hours?

Answer 1

Not very long, and sticking it in ice won't help much.

Dry ice is solid carbon dioxide, which changes (sublimes in fact, since it doesn't become liquid first) from gas to solid at about -78 celsius. Water ice freezes at about 0 celsius. Even if you put dry ice in a home freezer, it will still change back to gas.

So if you stick a bucket containing dry ice and water ice in the sun, the whole bucket will start warmer than the temparature needed to keep the dry ice solid, and will continue to warm up.   The water ice will keep the bucket cooler than if you just had dry ice sitting in the sun, but still way above -78.

If you had the dry ice in an insulating box (such as polystyerene) and out of direct sun and had a fair amount of dry ice, you'd probably find the inside of the box would still be cold and you'd still have bits of dry ice at the end of the day.

Answer 2

Depends on how much dry ice you have and the temperature, but, if you have a brick size it would probably last 3 to 5 minutes in direct sunlight on a hot day.

Answer 3

It'll dissipate away into a mist pretty quickly.  Water and ice will make it dissipate quicker.

I've seen people  use dry ice wrapped up in rags to keep the cold in and layered in a cooler to keep foods cold or frozen on camping trips.  The more closed up it was, and the better wrapped up the pieces of dry ice were, the longer it lasted.

You should Google it.