This is a true statement. A corrosive substance is one that will damage other materials with which is comes into contact. Corrosion of metals is another term for oxidation, and acids tend to oxidize metals. The degree of corrosion depends on the strength and concentration of the acid and on the reactivity of the metal. Hydrochloric acid oxidizes zinc according to the following equation:
`2HCl + Zn -> ZnCl_2 +H_2`
Oxidation is the loss of electrons. It occurs simultaneously with reduction, which is the gain of electrons. In this reaction zinc is oxidized from Zn to Zn2+ by the H+, and the H2+ is reduced to H+.
Acid can be used to clean metal by removing a thin surface layer. Acid rain causes corrosion to metals such as building components and vehicle parts. It also speeds up the corrosion caused by metals in contact with each other because it provides an aqueous ionic environment in which electrons are more easily transferred.
Acids also damage other materials that aren't metals. Acids can cause chemical burns to the skin. Acid precipitation causes the degradation of limestone statues and architecture. Limestone is calcium carbonate.