Question

In the change represented by the equation CO2(s) to CO2(g) the CO2(s) is

Answer 1

Answer: $CO_2(s)$ represent solid form of carbon-dioxide gas in the reaction.

Explanation:

In the given reaction solid phase of carbon-dioxide is changing directly into gaseous phase of carbon-dioxide. This process of changing of substance from solid to gaseous state directly by escaping the liquid state is known as Sublimation.

$CO_2(s)\overset{sublimation}\rightarrow CO_2(g)$

Here $CO_2(s)$ is representing the solid state of carbon-dioxide which is also known as Dry-ice.

Answer 2

The change represented

CO2(s) is dry ice and it converts into CO(g) which is gaseous carbon dioxide. The earth temperature is also warm for carbon dioxide to be firm in  solid form so it vaporizes. The method is very alike to the method of boiling. But that the atmospheric pressure is too low to permit carbon dioxide to convert into a liquid. Then it boils to form gas.