Who knows how to make dry ice?!
Answers: does anyone know how t make dry ice?
dry ice is carbon dioxide in it's solid form...maybe get in touch with a chemist?
it is a complex chemical process and occurs at extreemly cold temps with liquid nitrogen- just buy it
dry ice is frozen carbon dioxide. i think it's about -110 degrees fahrenheit. you need special equipment to make it. Just buy some.
i doubt you can make it.... just buy some
unless you have a tank of carbon dioxide, and something to freeze it with
Making dry ice
Solid carbon dioxide is known as dry ice. It sublimes at –78°C becoming an extremely cold gas. It is often used in theatres or nightclubs to produce clouds (looking a bit like smoke). Because it is more dense than the air, it stays low. It cools the air and causes water vapour in the air to condense into tiny droplets – hence the clouds.
It is also useful in the Physics (and Chemistry) laboratory.
Safety
Wear eye protection and gauntlet-style leather gloves when making or handling solid carbon dioxide.
Uses
Dry ice has many uses. As well as simply watching it sublime, you could also use it for cloud chambers, dry ice pucks, cooling thermistors and metal wire resistors in resistance experiments. It can also be used in experiments related to the gas laws.
Obtaining dry ice
There are two main methods of getting a source of dry ice.
1 Using a cylinder of carbon dioxide
It is possible to make the solid 'snow' by expansion before the lesson begins and to store it in a wide-necked Thermos flask.
Remember that the first production of solid carbon dioxide from the cylinder may not produce very much, because the cylinder and its attachments have to cool down.
What type of cylinder, where do I get CO2, and what will it cost?
A CO2 gas cylinder should be fitted with a dip tube (this is also called a ‘siphon type’ cylinder). This enables you to extract from the cylinder bottom so that you get CO2 in its liquid form, not the vapour.
NOTE: A plain black finish to the cylinder indicates that it will supply vapour from above the liquid. A cylinder with two white stripes, diametrically opposite, indicates it has a siphon tube and is suitable for making dry ice.
A cylinder from British Oxygen will cost about ￡80 per year for cylinder hire and about ￡40 each time you need to get it filled up. (The refill charge can be reduced by having your chemistry department cylinders filled up at the same time.)
Don't be tempted to get a small cylinder - it will run out too quickly.
If the school has its own CO2 cylinder there will be no hire charge, but you will need to have it checked from time to time (along with fire extinguisher checks). Your local fire station or their suppliers may prove a good source for refills.
CLEAPSS leaflet PS45 Refilling CO2 cylinders provides a list of suppliers of CO2.
A dry ice attachment for the cylinder
Dry ice disks can be made using an attachment that fits directly on to a carbon dioxide cylinder with a siphon tube. Section 13.3.1 of the CLEAPSS Laboratory Handbook explains the use of this attachment (sometimes called Snowpacks or Jetfreezers). This form is most useful for continuous cloud chambers and low-friction pucks.
You can buy a Snowpack dry ice maker from Scientific and Chemical. Type ‘dry ice’ into their cat no/description box. The product number is GFT070010
VWR International sells Snowpacks through its UK distributor. The version that makes 30 g pellets of dry ice is catalogue number 3285042/02.
Philip Harris sells similar products, see catalogue number C7A57812. (The dry ice attachment comes with safety gloves).
2 Buying blocks or pellets
Blocks of solid carbon dioxide or granulated versions of it can be obtained fairly easily with a search on the Internet. Local stage supply shops or Universities may be able to help. It usually comes in expanded foam packing; you can keep it in this packing in a deep freeze for a few days.
The dry ice pellets come in quite large batches. However, they have a number of uses in science lessons so it is worth trying to co-ordinate the activities of different teachers to make best use of your bulk purchase.