Answer: [tex]\Delta S[/tex]< 0
Explanation:
Entropy is the measure of randomness or disorder of a system. If a system moves from an ordered arrangement to a disordered arrangement, the entropy is said to decrease and vice versa.
For the reaction [tex]CaO(s)+CO_2(g)\rightarrow CaCO_3(s)[/tex]
In this reaction gaseous reactants are converting to solid products. The randomness will decrease and hence entropy will also decrease. Thus [tex]\Delta S[/tex] is negative or less than zero.