Chapter 4 Nomenclature

In the old days compounds had common names like: water, milk of magnesia, gypsum, quicklime, blue vitriol Today we know of over 4 million compounds. Common names won’t work binary compounds are compounds made of two elements There are two classes: 1) metal & nonmetal 2)nonmetal & nonmetal

4.1 Naming Compounds that Contain a metal and a Nonmetal Metals tend to… (electrons) lose electrons Nonmetals tend to… (electrons) gain electrons Metals will have a ______ charge Nonmetals will be ________ These get together to form neutral binary ionic compounds There are 2 Types… positive negative

Type I Binary ionic compounds The metals must be from Group 1, 2, or Al3+, Ga3+, In3+, Zn2+, Cd2+, Ag+ The cation (usually a metal) is listed first and the anion (usually a nonmetal) second The subscripts in the formula must produce an electrically neutral formula unit. 3. The subscripts are the smallest whole numbers possible. 4. The cation takes the name of its element (e.g. Li+ would be called "Lithium“) 5. The anion name uses the first part of its elemental name, and subsequently adding the suffix "-ide". (e.g. Br- would be called "Bromide“)

Anion Name H- Hydride F- Fluoride Cl- Chloride Br- Bromide I- Iodide O2- Oxide S2- Sulfide Se2- Selenide N3- Nitride P3- Phosphide As3- Arsenide C4- Carbide

Example Cation Anion Formula Na Cl

Example Cation Anion Formula Na+ Cl-

Example Cation Anion Formula Na+ Cl- NaCl

Example Cation Anion Formula Ca Br

Example Cation Anion Formula Ca2+ Br-

Example Cation Anion Formula Ca2+ Br- CaBr2

Example Cation Anion Formula Na S

Example Cation Anion Formula Na+ S2-

Example Cation Anion Formula Na+ S2- Na2S

Example Cation Anion Formula Mg O

Example Cation Anion Formula Mg2+ O2-

Example Cation Anion Formula Mg2+ O2- MgO

Example Cation Anion Formula Al O

Example Cation Anion Formula Al3+ O2-

Example Cation Anion Formula Al3+ O2- Al2O3

Questions? 21

Type II binary ionic compounds Type II ions can form more than one cation The substance on the right is iron chloride iron canform either 2+ or 3+ ions “but Mr. Farrin, how do we know which iron is in iron chloride? Fe2+ or Fe3+?” “By the use of Roman numerals” e.g. iron (III) chloride

Type II binary ionic compounds Write the formula for iron (III) chloride Fe3+ Cl1- FeCl3 23

what is the name of FeCl2? Which iron is it? Chloride always has a 1- charge, and there are two of them To balance that, the positive ion must have a total charge of… 2+ There is only one cation so it must have the whole 2+ charge all to itself Therefore it must be… iron(II) chloride

Common Type II Cations Ion Systematic Name Fe3+ iron(III) Cu2+ copper(II) Cu+ copper(I) Co3+ cobalt(III) Co2+ cobalt(II) Sn4+ tin(IV) Sn2+ tin(II) Pb4+ lead(IV) Pb2+ lead(II) Hg2+ mercury(II) Hg22+ mercury(I)

examples CuCl copper(I) chloride mercury(II) oxide HgO (what would mercury (I) oxide look like?) Hg2O Fe2O3 iron(III) oxide Mn2O4 manganese(IV) oxide lead(IV) chloride PbCl4

Questions?

4.2 Naming Binary Compounds that Contain only Nonmetals (Type III) Type III contain only nonmetals Prefixes are used to show how many atoms of each element are in each molecule Number of Atoms Prefix 1 mono 6 hexa 2 di 7 hepta 3 tri 8 octa 4 tetra 9 nona 5 penta 10 deca

examples BF3 boron trifluoride NO nitrogen monoxide dinitrogen pentoxide N2O5 PCl5 phosphorus pentachloride sulfur hexafluoride SF6 SO2 sulfur dioxide examples

4.3 naming binary compounds: a review

Questions? 32

4.4 Naming Compounds that contain Polyatomic Ions There is another type of compound, that involves ions Polyatomic ions: ions with more than one type of atom Notice many have O in them, they are called oxyanions

In order to recognize that polyatomic ions are present (when given names), look for the following: root-ate root-ite hypo-root-ite per-root-ate

examples Na2SO4 sodium sulfate Fe(NO3)3 iron(III) nitrate manganese(II) hydroxide Mn2+ (OH)- Mn(OH)2

examples Na2CO3 sodium carbonate iron(III) bromide FeBr3 PCl3 phosphorus trichloride cesium perchlorate CsClO4 CuSO4 copper(II) sulfate examples 36

Nomenclature Flowchart

4.5 Naming Acids What do we know about acids? taste sour pH below 7 react with most metals turn blue litmus paper red H+ donor Acetic acid, (HC2H3O2) Hypochlorous acid (HClO) hydrochloric acid (HCl)

4.5 Naming Acids When the anion does NOT contain Oxygen: Acetic acid, (HC2H3O2) Hypochlorous acid (HClO) hydrochloric acid (HCl) When the anion does NOT contain Oxygen: Use the prefix hydro + root of the anion’s name – ic + the word acid Example: HCl - hydrochloric acid

4.5 Naming Acids When the anion contains Oxygen: Acetic acid, (HC2H3O2) Hypochlorous acid (HClO) hydrochloric acid (HCl) When the anion contains Oxygen: The name will depend on the name of the polyatomic anion. -ate → -ic + the word acid -ite → -ous + the word acid

4.5 Naming Acids Examples HBr hydrobromic acid H2SO4 sulfuric acid sulfurous acid Examples hydroflouric acid HF phosphoric acid H3PO4 nitrous acid HNO2

4.5 Naming Acids Questions?