BEWARE!!! There is a lot memorization involved with this chapter. Chapter 4 Nomenclature BEWARE!!! There is a lot memorization involved with this chapter.

In the old days compounds had common names like: water, milk of magnesia, gypsum, quicklime, etc. Today we know of over 4 million compounds. Common names won’t work Therefore we have a system! First we will learn about binary compounds, compounds made of two elements There are two classes: 1) metal/nonmetal (ionic) 2) nonmetal/nonmetal (covalent)

4.1 Naming Compounds that Contain a metal and a Nonmetal Metals tend to lose electrons e-, Nonmetals gain electrons e- Metals like to be positive + Nonmetals like to be negative - These get together to form binary ionic (M with NM) compounds

When writing the formula the cation is first, anion second When naming just say their names Some cations have only one charge ever (called Type I ion) Some have more than one charge (Type II ion) There are also Type I compounds and Type II compounds KNOW YOUR IONS!!!

Type I Binary ionic compounds Reviewing the rules:

Type II binary ionic compounds Some cations can form more than one charge!!! (Type II ion!) Let’s look at an example…. iron can form 2+ and 3+ ions so what is the iron in iron chloride? Fe2+ or Fe3+? must be a way to distinguish the two! use Roman numerals…

So what is the name of FeCl2? Chloride always has a 1- charge, and there are two, so… The positive guy must have a total 2+ charge, and… There is only one cation so it get the whole 2+ charge all to itself, so… It must be iron(II), so… It is iron(II) chloride Know Table 4.2 (the systematic is emphasized in this class!!)

examples CuCl copper(I) chloride HgO mercury(II) oxide Fe2O3 iron(III) oxide Mn2O4 manganese(IV) oxide PbCl4 lead(IV) chloride

summary of Type I and Type II

summary examples CoBr2 cobalt(II) bromide CaCl2 calcium chloride Al2O3 aluminum oxide CrCl3 chromium(III) chloride summary examples

4.2 Naming Binary Compounds that Contain only Nonmetals (Type III) Type III contain only NM! think prefixes! (note: water and ammonia are Type III but always keep their common names)

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

4.3 naming binary compounds: a review

4.4 Naming Compounds that contain Polyatomic Ions There is another(!) type of compound, one that involves… Polyatomic ions. Ions with more than one type of atom in it gotta know Table 4.4

Notice many have O in them Called oxyanions Most common is called root-ate (e.g. sulfate) One less O than most common? root-ite (nitrite) One less than that? hypo-root-ite (hypochlorite) One more than most common? per-root-ate (perchlorate) Must be able to recognize Polyatomic ions!!!

examples Na2SO4 sodium sulfate Fe(NO3)3 iron(III) nitrate Mn(OH)2 parentheses here mean there are 3 of what’s inside. “NO33” is nonsense! iron(III) nitrate Mn(OH)2 manganese(II) hydroxide examples

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

4.5 Naming Acids Some things when dissolved in water can lose an H+ right off them called acids taste sour know these! have their own name system…

4.6 Writing Formulas from Names so far we’ve done formulas to names… now we do reverse! yippee! you HAVE TO KNOW all the names I warned you about!!!

examples potassium hydroxide KOH sodium carbonate Na2CO3 nitric acid HNO3 calcium chloride CaCl2 dinitrogen pentoxide N2O5 ammonium perchlorate NH4ClO4 examples

if this helps, use it. if it doesn’t, don’t!