Formulas Flowchart - Lecture notes 1 PDF

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Dr. F...

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Nomenclature: Writing Formulas Flowchart Refer to the "Reference Sheet for Chemical Nomenclature" for tables of ions and prefixes.

Ionic or Molecular? decision

decision

Ionic

Molecular

Contains metal or “ammonium” (NH4+) in name

Contains all non-metal atoms (except ammonium compounds like NH4Cl) question

ACTION

Acid (HnX) or Not ? acids contain “acid” in name decision

Write Cation 1st  Main group Metal – predict charge using Periodic Table  Transition Metal – the Roman numeral gives the charge  Ammonium – NH4+1 Write Anion 2nd  monatomic – has “-ide” ending (except hydroxide, cyanide). Predict charge using Periodic Table  polyatomic – has “-ite” or “-ate” ending or is hydroxide or cyanide. You just have to know these – name, formula and charge! Determine Proper Subscripts for each ion:  do “switcheroo” – make each charge the subscript on the opposite ion!  Place parentheses around any polyatomic ion if subscript > 1  reduce subscripts to lowest forms if needed Ex: “chromium(IV) sulfate” 1. Cr4+ SO422. Cr2 (SO4)4 – subscripts reducible! 3. Final: Cr(SO4)2

Acid Has H followed by some ion formula

decision

Not Acid

ACTION

ACTION

KNOW THESE: HCl = hydrochloric acid HNO3 = nitric acid H2SO4 = sulfuric acid HC2H3O2 = acetic acid be ready to learn new as needed

Place Least Electronegative element first  usually 1st in name (many exceptions here)  “farthest from King Fluorine”  numerical prefix gives the subscript Place other element second  numerical prefix gives subscript  DO NOT REDUCE subscripts for molecular compounds – these are molecular formulas and give actual atom counts (not just ratios like ionic) Ex: “dinitrogen trioxide” = N2O3 “tertraphosphorous hexoxide” = P4O6...