Question

What do you mean by solid ice. why co2 is kept under the low pressure.

Answer 1

I think it should be dry ice .

dry ice ==> Dry ice, sometimes referred to as "cardice", is the solid form of carbon dioxide. It is used primarily as a cooling agent. Its advantages include lower temperature than that of water ice and not leaving any residue .

Answer 2

when co2 is subjected to high pressure , it converts into solid co2 i.e called dry ice.Co2 is kept under low pressure so that it remains in gaseous state.