Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Naming the Inorganic Compounds Kavita Gupta Classification of Compounds for Naming Purposes Ionic compounds • Formed by a metal and a nonmetal or a polyatomic ion • Generally solids in the natural state • Ex: NaCl, K2SO4, PbCO3, ZnS, KMnO4 Molecular Compounds • Made up exclusively of nonmetals • Generally liquids or gases in natural state • Ex: NO2, CO2, P2O5, H2O Acids • Begin with a H • Generally present as aqueous solutions or gases • HCl, HClO4, H2CO3, HNO3, HC2H3O2, HCOOH www.fransonchiropractic.com Naming the Ionic Compounds Ionic Compoundsmade of a cation (either from group 1, group 2 or transition metals) and an anion (monoatomic or polyatomic anion) Anions are named the same for any ionic compounds. Monoatomic anion ends in –ide and polyatomic anion is named just like the name of the polyatomic anion. Cation from Transition Metal Old Way of Naming: Lower of the two charges cation name ends in –ous and higher of the two charges cation name ends in – ic. Stock Way:Name the cation as its element, followed by its oxiation number (Charge) within parenthesis. Cation from Group 1 (alkali metal) or Group 2 (alkaline earth) Name the cation as the element. Practice on Naming Ionic Compounds Ionic Compounds with Cations from Group 1 and 2 Na2SO4 KClO4 Ionic Compounds with cations from transition metals PbS Cu(NO3)2 Criss Cross Method for writing the formula for an ionic compound given its name Criss-cross method involves bringing the valency (charge) of one element down as a subscript next to the other element or polyatomic ion. •Practice writing the formula of the following compounds by using the criss-cross method. Sodium Sulfide Potassium Nitrate Ammonium Carbonate Cupric Nitride Ferrous Sulfate Naming the Molecular Compounds There are two ways of naming the molecular compounds Prefix Way Stock Way Ex: N2O5– Use prefixes mone-, di-, tri- etc. to indicate number of atoms of each element. Do not use mono before the first element. Nitrogen (V) Oxice Ex. N2O5- Di nitrogen Pentoxide CO2- Carbon Dioxide CO2- Carbon (IV) Oxide CO – Carbon (II) Oxide Write name of the first element followed by its oxidation state in parenthesis Naming the Acids To name an acid, first check to see if it is an oxy acid or not. Presence of Oxygen in the chemical formula of an acid indicates an oxyacid. Ex. HCl is not an oxyacid but HClO4 is an oxyacid. Oxyacids: Anion ending decides the name of the acid. If anion ends in –ate, then acid is –ic acid, if anion ends in –its, then acid is –ous acid. To name an acid without oxygen, start naming with Hydrofollowed by the name of anion ending in –ic Acid. Ex. HClO4 Perchloric Acid (anion perchlorate) Ex. HClO3 Chloric Acid (anion Chlorate) Ex. Ex. HCl Hydrochloric acid Naming of Complex Compounds Name cation first followed by anion. Within a complex, transition metal is named first with its charge listed within parenthesis, followed by ligands and then anion. If complex is anion, then its name ends in –ate. • Please go back to Ch 2 in the ibook for details on the naming of the complexes or coordination compounds. Naming of the Hydrates • Hydrates are ionic compounds that have loosely attached water molecules to them. Ex. CuSO4. 5H2O. • To name the hydrates, name the ionic compound first and then use the prefix that indicates the number of water molecules attached. • Ex. The name of CuSO4.5H2O is Cupric Sulfate pentahydrate or Copper (II) Sulfate pentahydrate. Common Cations with Variable Valency Cuprous, Cupric Copper Cu Cu + Cu 2+ Cobaltous, Cobatic Cobalt Co Co 2+ Co 3+ Ferrous, Ferric Iron Fe Fe 2+ Fe 3+ Plumbous, Plumbic Lead Pb Pb 2+ Pb 4+ Mercurous, Mercuric Mercury Stannous, Stannic Tin Hg Hg2 2+ Hg 2+ Sn Sn 2+ Sn 4+ Common Polyatomic Ions Ammonium NH4 + Chlorate ClO3 - Thiosulfate S2O3 2- Nitrate NO3 - Perchlorate ClO4 - Thiocynate SCN - Phosphate PO4 3- Chlorite ClO2 - Peroxide O2 2- Hydroxide OH - Hypochlorite ClO - Sulfite SO3 2- Nitrite NO2 - Phosphite PO3 3- Bisulfate (hydrogen sulfate) HSO4 - Sulfate SO4 2- Permanganate MnO4 - Carbonate CO3 2- Acetate Chromate CrO4 2- Bicarbonate (hydrogen carbonate) Dichromate Cr2O7 2- Cyanide C2H3O2 CH3COO HCO3 - CN - Oxide O 2-