How do the properties of Cr3 and Ga3 differ from those of Fe3 to make them useful for this purpose

The isotonic saline solution described in part a is connected to an unknown solution via a semipermeable membrane, the unknown solution level drops. based on this information, what can be said about these two solutions?

H2so4(aq) + mg(s)—> mgso4(aq) +h2(g) which substance is the acid in the reaction?

In an exothermic reaction the bonding energy of the product is: less than the reactants same as the reactants greater than the reactants dependent upon the presence of a catalyst