i know what aluminum is but oxide is not found on the periodic table, and the teacher also gave us a list of common oxidation numbers for polyatomic ions and it is not there also, can anyone help me?
Aluminum Oxide = Al2O3 Oxidation number of Al = +3 Oxidation number of O = -2 1 mol of Al weights 26.98 g | 1 mol of O weights 16 g You have to atoms of Al, so: 26.98 *2 = 53.96 g/mol You have 3 atoms of O = 16 *3 = 48 g/mol 53.96 + 48 = 101.96 g/mol == Molar mass of Al2O3 That means that in 1 mol of Al2O3 weights 101.96 g
oxide means oxygen.. atomic mass of roughly 16. Al2O3 so 2 Al which has an atomic mass of 27 each and then three O which have an atomic mass of 16 each.. so add it up and you get 102
Aluminum Oxide is just the name of an ionic compound. Kind of like Sodium Chloride. While there is no chloride atom, we know it's just that's the traditional way to name NaCl (table salt.) Aluminum Oxide just means it is aluminum and oxygen combined to form a charge neutral ionic compound. Since we know aluminum has a charge of 3+ (this can be obtained from the periodic table or a chart of cations) and Oxygen has a charge of 2- ( we can obtain this from the periodic table or a chart of anions), all we have to do is make a charge neutral species. In this case Al_2O_3 (those are subscripts) is the correct species because it is neutral. So now we just calculate the weight. Al = 26.98 O= 15.99 so we have 2 Al and 3 O 2 * (26.98) + 3 * (15.99) = 101.9 grams/mol
