Naming Simple Binary Compounds Element with the lowest group number is named first Covalent compound The Greek numerical prefixes are used for each elements forming the compound. “mono” is omitted for the first element. name of the first element + second element root + “ide” ex: CO is “carbon dioxide”, P O is “diphosphorous pentoxide” 2 2 5 (with a space between the two words) in the same group, the element with the highest period number is named first Ionic compound positive ion (cation) is named first, negative ion (anion) is named second name of the metal + anion root + “ide” ex: CaBr 2 is “calcium bromide” Since the charges are always balanced, the Greek prefix is useless It is a mistake to write: calcium di bromide Metal with several possible charges Ox anions Hydrated compound Ex: transition metal like Fe 2+ , Fe 3+ nonmetal bonded to 1 or more oxygen atom water molecule attached to the compound use roman numerical within parentheses family of two use the Greek prefix anion with the most oxygen atom: suffix “ate” with each water formula ex: FeCl 2 is “iron( II ) chloride” anion with the least oxygen atom: suffix “ite” unit “hydrate” 2- 2- ex: SO 4 is “sulfate ”, SO 3 is “sulfite ” ex: MgSO 4•7H 2O is the common name can also be used: “magnesium sulfate higher charge cation = suffix “ic” family of four (VIIA) heptahydrate” lower charge cation = suffix “ous” anion with 4 oxygen atom = “per-root -ate” 1: mono 6: hexa here, FeCl 2 is ferrous chloride anion with 3 oxygen atom = “ root -ate” 2: di 7: hepta anion with 2 oxygen atom = “ root -ite” 3: tri 8: octa never use the roman numerical for an ion that anion with 1 oxygen atom = “hypo-root -ite” 4: tetra 9: nona can have no more than one oxidation state ex: ClO - is “per chlorate ” 5: penta 10: deca 4 Acid (proton containing compound) Oxoacid (acid formed from oxoanions) For anion without oxygen: use non metallic root + suffix “ic” acid use prefix “hydro” + anion root + suffix “ic” acid anions with the suffix “ite” become “ous” ex: HBr (aq) is “hydrobromic acid” prefixes “hypo” and “per” are kept - ex: BrO 4 is the “perbromate” ion, the acid form HBrO 4(aq) is per bromic acid . http://place.dawsoncollege.qc.ca/~dbaril Common monoatomic ions Cations Anions Charge Formula Name Charge Formula Name 1+ H+ hydrogen 1- H- hydride Li + lithium F- fluoride Na + sodium Cl - chloride K+ potassium Br - bromide Cs + cesium I- iodide Ag + silver* 2+ Mg 2+ magnesium 2- O2- oxide Ca 2+ calcium S2- sulfide Sr 2+ strontium Ba 2+ barium Zn 2+ zinc* Cd 2+ cadmium* 3+ Al 3+ aluminum 3- N3- nitride * transition element Some metals that form more than one monoatomic ion. Element Ion formula Systematic name Common name Chromium Cr 2+ chromium(II) chromous Cr 3+ chromium(III) chromic Cobalt Co 2+ cobalt(II) Co 3+ cobalt(III) Copper Cu + copper(I) cuprous Cu 2+ copper(II) cupric Iron Fe 2+ iron(II) ferrous Fe 3+ iron(III) ferric Lead Pb 2+ lead(II) Pb 4+ lead(IV) Manganese Mn 2+ manganese(II) Mn 3+ manganese(III) 2+ Mercury Hg 2 mercury(I) mercurous Hg 2+ mercury(II) mercuric Tin Sn 2+ tin(II) stannous Sn 4+ tin(IV) stannic http://place.dawsoncollege.qc.ca/~dbaril Group VIIA oxoanions ( family of four ) CHARGE of -1 chlorine bromine iodine ClO - hypochlorite BrO - hypobromite IO - hypoiodite - - - ClO 2 chlorite BrO 2 bromite IO 2 iodite - - - ClO 3 chlorate BrO 3 bromate IO 3 iodate - - - ClO 4 perchlorate BrO 4 perbromate IO 4 periodate oxoanion -1 -2 -3 - 2- 3- NO 2 nitrite SO 3 sulfite PO 4 phosphate - 2- NO 3 nitrate SO 4 sulfate other ions -1 -2 - 2- MnO 4 permanganate CrO 4 chromate - 2- CN cyanide Cr 2O7 dichromate - 2- OCN cyanate O2 peroxide - 2- SCN thiocyanate CO 3 carbonate - 2- CH 3COO acetate C2O4 oxalate - 2- OH hydroxide S2O3 thiosulfate +1 + NH 4 ammonium + H3O hydronium addition of an hydrogen will reduce the charge of the anion - HCO 3 hydrogen carbonate (bicarbonate) -1 - HSO 4 hydrogen sulfate (bisulfate) -1 2- HPO 4 hydrogen phosphate (biphosphate) -2 - H2PO 4 dihydrogen phosphate -1 http://place.dawsoncollege.qc.ca/~dbaril Naming compounds: Test yourself. Provide a name for each compound: 1) N2O4 2) CO 3) H2O 4) C2H6 5) NaCl 6) CaCl 2 7) CuBr 8) Fe 2(SO 4)3 9) LiClO 4 10) CuCl .6H 2O 11) NH 4OH 12) HCl (g) 13) HCl (aq) 14) HNO 3(aq) 15) H2SO 3(aq) Answers and explanations: 1) dinitrogen tetraoxide : first part is the name of the element, second part is the second element root ending with “– ide”; A space is required between the two parts. A covalent compound (made from nonmetal) always required the greek prefix to tell the number of atoms of each type in a compound . 2) carbon monoxide : the prefix “mono” is never used for the first atom. 3) water : some compound are widely used in chemistry, in this case, they have a common name (NH 3 = ammonia, CH 4 = methane, etc.) . 4) ethane . 5) sodium chloride : ionic compound are made from a metal (here Na) and a non metal (Cl), the cation is named first. greek prefix are never used in ionic compounds since the ratio of Na + and Cl - is known by simply balancing the charges . 6) Calcium chloride : Ca +2 request 2 Cl - ions to keep its electroneutrality . 7) Copper( I) bromide : Copper is a transition element that can get several oxidation states like Cu + or Cu 2+ . In this case, the oxidation state should be indicated with a roman number within parentheses. 8) Iron( III ) sulfate : Since the total charge brought by the three sulfates is –2x3 = -6, then each of the two irons should have +3 charge to neutralize the complex . 9) Lithium perchlorate : the perchlorate is an oxoanion based on chlorine, from the halogen group (family of 4 oxoanions, charge –1) . 10) Copper( I) chloride hexahydrate : We use the greek prefix followed by the word “hydrate” to count the number of water molecules in the compound. 11) Ammonium hydroxide : No metal here but it is an ionic compound since it is made of two polyatomic ions. Positive ion or cation always named first . 12) Hydrogen chloride 13) hydrochloric acid : the compound here is the same than (12) but it now in its acid form in water or in an aqueous state (aq.). To name an acid made from a compound having a anion without oxygen, the prefix “hydro-“ to the root of the anion followed by “–ic acid” is used. 14) nitric acid : When the anion have oxygen (here nitrate), the prefix “hydro” is not used. The termination of the anion name will change from “ate” to “ic” or from “ite” to “ous” also ending with acid . 15) Sulfurous acid : Since the anion name is “sulfite”, the acid form will become “-ous acid”. http://place.dawsoncollege.qc.ca/~dbaril .