Writing Formulas Chapter 6 (Chapter 9)

Rules for Naming Compounds Formula begins with a metal Formula does NOT begin with a metal ‘H’ in front NO ‘H’ in front 1 )Metal name * 2) Polyatomic name 1 ) Metal name * 2 ) Non metal ROOT + IDE Only 2 elements More than 2 elements 1 ) Name 1 st element 2 ) 2 nd element ROOT + IDE 3 ) Prefix needed for subscripts (di, tri, tetra, penta, hexa, hepta, octa, nona, deca) Only 2 elements More than 2 elements 1 ) Write HYDRO 2 ) 2 nd element ROOT + IC 3 ) Write ACID Polyatomic ends with ATE Polyatomic ends with ITE 1) Polyatomic ROOT + IC 2 ) Write ACID 1 )Polyatomic ROOT + OUS 2 )Write ACID Classic Names: add –OUS for lower charge/ -IC for higher charge to these roots (NH 4 + acts like a metal) *These metals use a Roman Numeral after their name to indicate it’s charge Copper (I) – Cu +1 Copper (II)- Cu +2 Mercury(I) – Hg 2 +2 Mercury(II) – Hg +2 Iron(II) – Fe +2 Iron (III) – Fe +3 Chromium (II) – Cr +2 Chromium(III) – Cr +3 Manganese(II) – Mn +2 Manganese(III) – Mn +3 Cobalt(II) – Co +2 Cobalt(III) – Co +3 Lead(II) – Pb +2 Lead(IV) – Pb +4 Tin(II) – Sn +2 Tin(IV) – Sn +4 Cupr - Mercur - Ferr - Chrom - Mangan - Cobalt - Plumb - Stann -

Rules for Writing Chemical Formulas Name begins with a metal Name does NOT begin with a metal ‘ACID’ in the nameNo ACID in Name 1 ) Write the metal symbol/charge 2 ) Write the non metal symbol/charge 3) Add subscripts if necessary to make it neutral (criss-cross) Ends with -IDE Ends with –ATE/-ITE 1 ) Write each element symbol [NO CHARGES USED HERE] [NO Polyatomic IONS HERE] 2) The Prefix IS the subscript (mono, di, tri, tetra, penta, hexa, hepta, octa, nona, deca) ‘HYDRO’ in frontNo ‘HYDRO’ in front 1 ) Write H +1 2 ) Write non metal symbol/charge 3 ) Add subscripts if necessary to make it neutral (criss-cross) Name ends with -IC Name ends with - OUS 1) Write H +1 2)Write Polyatomic ion that ends with -ATE 3) Add subscripts if needed to make it neutral 1) Write H +1 2)Write Polyatomic ion that ends with -ITE 3) Add subscripts if needed to make it neutral Classic Names: add –OUS for lower charge/ -IC for higher charge to these roots (Ammonium acts like a metal) *These metals use a Roman Numeral after their name to indicate it’s charge Copper (I) – Cu +1 Copper (II)- Cu +2 Mercury(I) – Hg 2 +2 Mercury(II) – Hg +2 Iron(II) – Fe +2 Iron (III) – Fe +3 Chromium (II) – Cr +2 Chromium(III) – Cr +3 Manganese(II) – Mn +2 Manganese(III) – Mn +3 Cobalt(II) – Co +2 Cobalt(III) – Co +3 Lead(II) – Pb +2 Lead(IV) – Pb +4 Tin(II) – Sn +2 Tin(IV) – Sn +4 Cupr - Mercur - Ferr - Chrom - Mangan - Cobalt - Plumb - Stann - 1 ) Write the metal symbol/charge 2 ) Write the polyatomic ion/charge 3) Add subscripts/parenthesis if necessary to make it neutral (criss-cross)

Rules for Writing Chemical Formulas 1.All molecules have a neutral charge 2.Subscripts are used when individual charges are not the same 3.Parenthesis are used ONLY WITH POLYATOMIC IONS that need a subscript to make it neutral 4.Two non metals have prefixes to indicate their subscripts 5.The charges of representative elements are known to be:

Charges for metals and non metals

K 2 SO 4 Potassium sulfate

BaC 2 O 4 Barium oxalate

HClO 2 Chlorous acid

(NH 4 ) 2 SO 3 Ammonium sulfite

MgCO 3 Magnesium carbonate

CBr 4 Carbon tetrabromide

P2O5P2O5 Diphosphorous pentoxide

HNO 3 Nitric Acid

NaHSO 3 Sodium hydrogen sulfite

H2C2O4H2C2O4 Oxalic acid

Al(C 2 H 3 O 2 ) 3 Aluminum acetate

Mg(OH) 2 Magnesium hydroxide

H 3 PO 3 Phosphorous Acid

HF Hydrofluoric Acid

Zn(ClO) 2 Zinc hypochlorite

LiH Lithium hydride

HClO 3 Chloric acid

Rb 2 S Rubidium sulfide

SrCrO 4 Strontium chromate

KMnO 4 Potassium permanganate

NaCN Sodium cyanide

Ca(HSO 3 ) 2 Calcium hydrogen sulfite

Ba(NO 3 ) 2 Barium nitrate

H 3 PO 3 Phosphorous acid

Ag 2 CrO 4 Silver chromate

ZnCO 3 Zinc carbonate

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SO 3 Sulfur trioxide

BeSe Beryllium selenide

AlN Aluminum nitride

NH 4 C 2 H 3 O 2 Ammonium acetate

PCl 3 Phosphorous trichloride

K 2 HPO 3 Potassium hydrogen phosphite

H 2 SO 4 Sulfuric acid

H2SH2S Hydrosulfuric acid

(NH 4 ) 2 C 2 O 4 Ammonium oxalate

HNO 2 Nitrous acid

Al 2 (SO 4 ) 3 Aluminum sulfate

LiClO 2 Lithium chlorite

Ag 2 Cr 2 O 7 Silver dichromate

Hl Hydroiodic acid

NaClO Sodium hypochlorite

NI 3 Nitrogen triodide

H 2 CrO 4 Chromic acid