Question

Why is it that CO2 should be under high pressure?

Answer 1

Because of there capacity of pressure

Answer 2

the CO2 solid carbon dioxideis kept under high pressure because it is known as dry ice and convert to this carbon dioxide into solid form, the very low temperature and high pressure is required as it is gas. so prevent the sublemation of dry ice, it is kept under the low temperature and high pressure. I hope this answer can help u.