In a physical change the appearance or form of the matter changes but the kind of matter in the substance does not. However in a chemical change, the kind of matter changes and at least one new substance with new properties is formed. The distinction between physical and chemical change is not clear cut.
The reactants are the substances on the left side, which react and give the products on the right side.
The reactants are Fe and O.
The product is Fe2O3.
The arrow to the right means that the reaction is going in only one direction — the only reaction happening at the moment is that Fe and O are making Fe2O3.
(s) means the substance is in the solid state, and (g) means in a gaseous state (or the substance is a gas in that reaction).
Copper choruses purpose is its used as a catalyst for organic and inorganic reactions , mordant for dyeing and printing textiles, pigment for glass and ceramics, wood preservative, disinfectant, insecticide, fungicide, and herbicide. (Not sure if you want the actual purpose of water or not)
The answer is yes I believe so.
it will expand as water moves into it.