Explain protection of metal from corrosion. Several models have been proposed to express the thickness of the oxide layer y as a function of time t. In the following discussion, k is a rate constant. A metal (M) forms an oxide with the formula M2O. // --> . Acids combined with metal carbonates produce a salt, water and carbon dioxide. When the oxide layer gives some protection, the parabolic law apply. An oxide is a chemical compound that contains at least one oxygen atom and one other element in its chemical formula. if(MSFPhover) { MSFPnav4n=MSFPpreload("_derived/obnomes_2.htm_cmp_zona2010_hbtn.gif"); MSFPnav4h=MSFPpreload("_derived/obnomes_2.htm_cmp_zona2010_hbtn_a.gif"); } 1. E.g lead oxide reacts with sodium hydroxide to form sodium plumbite and water. // --> 2MgO Oxides of some metals like lead and zinc are amphoteric i.e they react with both acid and base. oxidation number , and we must know them, there is no confusion with the oxides When a substance reacts chemically, both as a base or acid it termed as an amphoteric solution. Experimentally it was found that a metal oxide has formula M 0.98 O. Most of the Earth's crust consists of solid oxides, the result of elements being oxidized by the oxygen in air or in water. The densities of $$Al$$ and $$Al_2O_3$$ are 2.702 and 3.965 g/mL respectively. A basic oxide is an oxide which when combined with water gives off a base. Volume of Al2O3 = (26.98+24.00) (g/mol) / 3.965 (g/mL =12.86 mL / mol. Iron (II) oxide, black, used as pigment. Not all metal oxides form a scale. the stoichiometric nomenclature when all the atoms are nonmetals. // -->