Unformatted text preview: ot;ide" ending Sodium chloride Ionic compounds,though made up of positive and negative ions,must be electrically neutral.The net,or total,charge of the ions in a formula unit must be zero. Positive ions (cations)
Name Lithium ion Sodium ion Potassium ion Rubidium ion Cesium ion Magnesium Calcium ion Barium Aluminum ion Zinc ion Symbol Li+ Na+ K+ Rb+ Cs+ Mg2+ Ca2+ Ba2+ Al3+ Zn2+ Name
Chromium (II) ion Chromium(III) ion Iron(III) ion Iron(II) ion Symbol Cr2+ Cr3+ Fe3+ Fe2+ Cu+ Cu2+ Hg22+ Hg2+ Sn2+ Pb2+ Copper(I) ion Copper(II) ion Mercury(I) ion Mercury(II) ion Tin(II) ion Lead(II) ion Negative ions (anions) Name Hydride ion Fluoride ion Chloride ion symbol H F Cl Name Iodide ion Oxide ion Sulfide ion symbol I O2 S2- Writing formulas when names of compounds are given Write formulas for the compounds barium oxide,calcium fluoride,and iron(III) sulfide. Solution In each case, identity the cations and charges, based on periodic table group numbers or on oxidation states appearing as Roman numberals in names : Ba+,Ca2+,and Fe3+.Then identity the anions and their charges:O2-,F-,and S2- .Combine the cations and anions in the relative numbers required to produce electrically neutral formula units. barium oxide: one Ba2+and one O2- = BaO calcium fluoride: one Ca2+ and two F- =CaF2 iron(III) sulfide: two Fe3+ and three S2- = Fe2S3 Naming compound when their formulas are given. Write acceptable name for the compounds Na2S,AlF3,Cu2O. Solution Na2S : sodium sulfide AlF3 : aluminum fluoride Cu2O : copper(I) oxide Binary Compounds of Two Nonmetals If the two elements in a binary compound are both nonmetals instead of a metal and a nonmetal,the compound is a molecular compound.The method of naming these compounds is similar to that just discussed. For example HCl = hydrogen chloride Generally, we indicate relative numbers of atoms through prefixes:mono =1,di =2,tri =3, tetra =4,penta =5,hexa =6,and so on. SO2 = sulfur dioxide SO3 = sulfur trioxide B2Br4 = diboron tetrabromide When the prefix ends in a or o and the element name begins with a or o,the final vowel of the prefix is dropped for ease of pronunciation.For example,carbon monoxide, not carbon monooxide,and dinitrogen tetroxide,not dinitrogen tetraoxide.However, PI3 is phosphorus triiodide,not phosphorus triodide. In both the formula and the name,we write the element with the positive oxidation state first Binary Acids In maning acids we use the prefix hydro followed by the name of the other nonmetal modified with an ic ending. The most important binary acids are listed below HF (aq) = hydrofluoric acid HCl (aq) = hydrochloric acid HBr (aq) = hydrobromic acid HI (aq) = hydroiodic H2S (aq) = hydrosulfuric acid The symbol(aq) signifies a substance in aqueous(water) solution Polyatomic Ions In polyatomic ions,two or more atoms are jioned together by covalent bonds.These ions are commonly encountered,especially among the nonmetals.
Name cation Ammonoum ion Anions Some Common Polyatomic Ions Cyanide ion Hydroxide ion Hypochlorite ion Perchlotare i...
View Full Document
- Spring '10
- Molecule, Ion