CHEMICAL FORMULAS CO 2 Has 2 elements: carbon and oxygen Has 3 atoms 1 C atom and 2 O atoms C 6 H 12 O 6 Has 3 elements, and 24 atoms

NAMING IONIC COMPOUNDS First word NaCl Cation-(positive ion) if the charge is always the same write the name of the metal. Transition metals can have more than one type of charge. Indicate the charge with Roman numerals in parenthesis.

NAME THESE Na +1 Ca +2 Al +3 Fe +3 Fe +2 Pb +2 Li +1

Second Word NaCl Anions (negative ion) are always the same charge. Change the element ending to – ide Cl -1 Chloride

NAME THESE Cl -1 N -3 Br -1 O -2 Ga +3

WRITE THESE Sulfide ion iodide ion phosphide ion Strontium ion

POLYATOMIC IONS Groups of atoms that stay together and have a charge. Acetate C 2 H 3 O 2 -1 Nitrate NO 3 -1 Nitrite NO 2 -1 Hydroxide OH -1 Permanganate MnO 4 -1 Cyanide CN -1

NAMING BINARY IONIC COMPOUNDS Binary Compounds - 2 elements. Ionic - a cation and an anion. To write the names just name the two ions. Easy with Representative elements. Group A NaCl = Na + Cl - = sodium chloride MgBr 2 = Mg +2 Br - = magnesium bromide

NAMING BINARY IONIC COMPOUNDS The problem comes with the transition metals. Need to figure out their charges. The compound must be neutral. same number of + and – charges. Use the anion to determine the charge on the positive ion.

NAMING BINARY IONIC COMPOUNDS Write the name of CuO Need the charge of Cu O is -2 copper must be +2 Copper (II) oxide Name CoCl 3 Cl is -1 there are three of them = -3 Co must be +3 Cobalt (III) chloride

NAMING BINARY IONIC COMPOUNDS Write the names of the following KCl Na 3 N CrN Sc 3 P 2 PbO PbO 2 Na 2 Se

POLYATOMIC IONS IN COMPOUNDS At least three elements NaNO 3 CaSO 4 CuSO 3 (NH 4 ) 2 O

LiCN Fe(OH) 3 (NH 4 ) 2 CO 3 NiPO 4

WRITING FORMULAS The charges have to add up to zero. Get charges on pieces. Cations from name of table. Anions from table or polyatomic. Balance the charges by adding subscripts. Put polyatomics in parenthesis.

WRITING FORMULAS Write the formula for calcium chloride. Calcium is Ca +2 Chloride is Cl -1 Ca +2 Cl -1 would have a +1 charge. Need another Cl -1 Ca +2 Cl 2 -1

WRITE THE FORMULAS FOR THESE Lithium sulfide tin (II) oxide tin (IV) oxide Magnesium fluoride Copper (II) sulfate Iron (III) phosphide gallium nitrate Iron (III) sulfide

WRITE THE FORMULAS FOR THESE Ammonium chloride ammonium sulfide barium nitrate

THINGS TO LOOK FOR If cations have (), the number is their charge. If anions end in -ide they are probably off the periodic table (Monoatomic) If anion ends in -ate or -ite it is polyatomic

MOLECULAR COMPOUNDS (COVALENTLY BONDED) made of just nonmetals smallest piece is a molecule can’t be held together because of opposite charges. can’t use charges to figure out how many of each atom

EASIER Molecular compounds name tells you the number of atoms. Uses prefixes to tell you the number

PREFIXES 1 mono- 6 hexa- 2 di- 7 hepta- 3 tri- 8 octa- 4 tetra- 9 nona- 5 penta- 10 deca-

PREFIXES To write the name write two words One exception is we don’t write mono- if there is only one of the first element. No double vowels when writing names (oa oo) PrefixnamePrefixname-ide

NAME THESE 1.N 2 O 2. NO 2 3. Cl 2 O 7 4. CBr 4 5. CO 2 6. BaCl 2

WRITE FORMULAS FOR THESE 1. diphosphorus pentoxide 2. tetraiodide nonoxide 3. sulfur hexaflouride 4. nitrogen trioxide 5. Carbon tetrahydride 6. phosphorus trifluoride 7. aluminum chloride

ACIDS WRITING NAMES AND FORMULAS

ACIDS Compounds that give off hydrogen ions when dissolved in water. Must have H in them. will always be some H next to an anion. The anion determines the name.

NAMING ACIDS If the anion attached to hydrogen is ends in -ide, put the prefix hydro- and change - ide to -ic acid HCl - hydrogen ion and chloride ion hydrochloric acid H 2 S hydrogen ion and sulfide ion hydrosulfuric acid

NAMING ACIDS If the anion has oxygen in it it ends in -ate of -ite change the suffix -ate to -ic acid HNO 3 Hydrogen and nitrate ions Nitric acid change the suffix -ite to -ous acid HNO 2 Hydrogen and nitrite ions Nitrous acid

NAME THESE 1. HF 2. H 3 P 3. H 2 SO 4 4. H 2 SO 3 5. HCN 6. H 2 CrO 4

WRITING FORMULAS Hydrogen will always be first name will tell you the anion make the charges cancel out. Starts with hydro- no oxygen, -ide no hydro, -ate comes from -ic, -ite comes from -ous

WRITE FORMULAS FOR THESE 1. hydroiodic acid 2. acetic acid 3. carbonic acid 4. phosphorous acid 5. hydrobromic acid