Consider the following reversible reaction. C(s) + O2(g) C02(9)
What is the equilibrium constant expression for the given system?
[CO]
o kor" (CO2)
[CO]
o KooTO]
[C]O2]
o Keg"
[CO2]
[02]
o Ker-1002]

The equilibrium constant expression for the given system is

Explanation:

Equilibrium constant is defined as the ratio of concentration of products to the concentration of reactants each raised to the power their stoichiometric coefficients. It is represented by

For a general chemical reaction:

The is written as:

The concentration of pure solid and pure liquid are taken as 1 in equilibrium expression.

The for the given reaction is written as:

answer is: c. the experiment shows that the red substance experienced a chemical change.

this is chemical change (chemical reaction), because two new substances are formed (metalig liquid and gas), the atoms are rearranged and the reaction is followed by an energy change.

this is example of chemical decomposition.

chemical decomposition (analysis) is the separation of a single chemical compound into its two or more elemental parts or to simpler compounds.  

chemical decomposition is opposite of chemical synthesis.