NAMING COMPOUNDS CH. 6.3

We use the word, COMPOUND, when describing an ionic bonded molecule. An example: –NaCl is sodium chloride

Elements you should know: H= hydrogen He = helium Li = lithium Be = beryllium B = boron C = carbon N = nitrogen O = oxygen

F = fluorine Ne = neon Mg = magnesium Al = aluminum Si = silicon P = phosphorus S = sulfur Cl = chlorine

Ar = argon Ca = calcium Zn = zinc Na = sodium K = potassium Fe = iron Cu = copper Ag = silver Sn = tin Au = gold Hg = mercury Pb = lead

You will be also given a list of polyatomic ions to use What?!

Polyatomic ion = a compound that has extra or missing electrons to give the overall compound a charge (+ or -) These polyatomic ions behave chemically as if they were a single atom EX: OH - –NO 3 - –SO 4 -

Naming RULES! Rule #1: If two identical elements combine, then the name doesn’t change examples: –O 2 = oxygen –H 2 = hydrogen –N 2 = nitrogen –F 2 = fluorine –Cl 2 = chlorine –Br 2 = bromine

Rule #2 When two elements join and one is a halogen, oxygen or sulfur, the name ends with - ide example magnesium + oxygen  magnesium oxide

let’s practice sodium + chlorine  magnesium + fluorine  lithium + iodine  chlorine + copper  oxygen + iron  KBr  LiCl 

CaO  MgS  KF 

let’s practice sodium + chlorine  sodium chloride magnesium + fluorine  magnesium flourided lithium + iodine  lithium idodide chlorine + copper  copper chloride oxygen + iron  iron oxide KBr  potassium bromide LiCl  lithium chloride

CaO  calcium oxide MgS  magnesium sulfide KF  potassium flouride

Rule #3 when 3 or more elements combine and two of them are H and O, the name ends with “hydroxide” e.g. sodium + hydrogen + oxygen  sodium hydroxide

practice: potassium + hydrogen + oxygen  LiOH  CaOH  Mg(OH) 2 

practice: potassium + hydrogen + oxygen  LiOH  lithium hydroxide CaOH  calcium hydroxide Mg(OH) 2  magnesium hydroxide

Rule #4  When 3 or more elements combine and one of them is oxygen, the ending is -ate e.g. copper + sulfur + oxygen  copper sulfate

more practice calcium + carbon + oxygen  potassium + carbon + oxygen  calcium + sulfur + oxygen  calcium + oxygen + nitrogen 

AgNO 3  H 2 SO 4  K 2 CO 3 

more practice calcium + carbon + oxygen  calcium carbonate potassium + carbon + oxygen  potassium carbonate calcium + sulfur + oxygen  calcium sulfate calcium + oxygen + nitrogen  calcilum nitrate

AgNO 3  silver nitrate H 2 SO 4  hydrogen sulfate (aka: sulfuric acid) K 2 CO 3  potassium carbonate

Some compounds have “unique names” H 2 O  water CO 2  carbon dioxide NH 3  ammonia SO 2  sulfur dioxide

How do you know what subscripts to use? You need to know what ion the element becomes, based on its location on the periodic table.

Group 1A (alkali metals) all have 1+ Group 2A (alkaline metals) all have 2+ Group 3A (metalloids) have 3+ Group 4 A tend to form covalent bonds Group 5A (nitrogen family) have -3 Group 6A (oxygen family) have -2 Group 7A (halogens) have -1

Practice! It’s easier to learn by doing!!!