Question

A solid form of $C{{O}_{2}}$ called _________, is produced by supercooling heated $C{{O}_{2}}$ at extreme pressure in a diamond anvil.
(A)- Dry ice
(B)- Germania gas
(C)- Silica glass
(D)- Carbonia glass

Answer 1

The carbon-dioxide gas can attain various states of solid and liquid, with the varying pressure and temperature conditions. The extreme pressure makes the carbon-dioxide to change from gas to a solid glass-like form which has strong covalent-bonds formed.

Complete step by step answer:
In the diamond anvil cell, extreme high pressure can be attained on the material placed in it. It works on the principle that on a small area, by applying moderate force, a high pressure is obtained. Also, the diamond used in this method is very hard and incompressible.
The carbon-dioxide, at low pressure and temperature, the gas is directly converted to the solid form, near the sea level whereas above it gets converted from solid to gas directly (sublimes). This solid form is called a dry-ice.

At higher pressure, another solid-form of carbon-dioxide is possible in amorphous glass-like solid which shows the presence of covalent bonding in the network structure. It is obtained by subjecting the dry ice under extreme pressure in the diamond anvil. This solid form is called the Carbonia glass.

Note: The amorphous solid form of the carbon -dioxide is of great importance as it can form a stable protective layer on mixing with silica, thus forming a hard and stiff glass-like coating at room temperatures. The silica and germanium belonging to the same group of carbon atoms, also exist in the analogous glass-state known as the silica-glass and Germania glass respectively.