Question: Does the compound Carbon dioxide need to be in a particular state to be turned into a useful material?

Helen Pritchard-Smith answered on 18 Jun 2013:

I use it in its normal state i.e. gaseous. Some people use it to make carboxylic acids in liquid form this is called supercritical carbon dioxide.

Some of the reactions i do need to be really cold so we use solid carbon dioxide (card ice) which is stored at -78 C . You mix it with a solvent like ethanol, each solvent makes a different temperature so you can control the temperature of your reaction based on the solvent you select to mix with the card ice. It is really cold and will burn you if you held it in your hands, it feels the same as if you burn yourself on something hot.