Copyright©2000 by Houghton Mifflin Company. All rights reserved. 1

2 The Chemists’ Shorthand: Formulas Chemical Formula: Symbols = types of atoms Subscripts = relative numbers of atoms CO 2 Structural Formula: Individual bonds are shown by lines. O=C=OO=C=O

Copyright©2000 by Houghton Mifflin Company. All rights reserved. 3 Ions Cation: A positive ion Mg 2+, NH 4 + Anion: A negative ion Cl , SO 4 2  Ionic Bonding: Force of attraction between oppositely charged ions.

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Copyright©2000 by Houghton Mifflin Company. All rights reserved. 5 Periodic Table Elements classified by:  properties  atomic number Groups (vertical) 1A = alkali metals 2A = alkaline earth metals 7A = halogens 8A = noble gases Periods (horizontal)

Copyright©2000 by Houghton Mifflin Company. All rights reserved. 6 Naming Compounds 1. Cation first, then anion 2. Monatomic cation = name of the element Ca 2+ = calcium ion 3. Monatomic anion = root + -ide Cl  = chloride CaCl 2 = calcium chloride Binary Ionic Compounds:

Copyright©2000 by Houghton Mifflin Company. All rights reserved. 7 Naming Compounds (continued)  metal forms more than one cation  use Roman numeral in name PbCl 2 Pb 2+ is cation PbCl 2 = lead (II) chloride Binary Ionic Compounds (Type II):

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Copyright©2000 by Houghton Mifflin Company. All rights reserved. 9 Naming Compounds (continued)  Compounds between two nonmetals  First element in the formula is named first.  Second element is named as if it were an anion.  Use prefixes  Never use mono- P 2 O 5 = diphosphorus pentoxide Binary compounds (Type III):

Copyright©2000 by Houghton Mifflin Company. All rights reserved. 10 Practice naming these v arious chromium compounds dissolved in water. From left to right; CrCl 2, K 2 Cr 2 O 7, Cr(NO 3 ) 3, CrCl 3, K 2 CrO 4.

Copyright©2000 by Houghton Mifflin Company. All rights reserved. 11 CrCl 2 Chromium (II) Chloride K 2 Cr 2 O 7 Potassium Dichromate Cr(NO 3 ) 3 Chromium (III) Nitrate CrCl 3 Chromium (III) Chloride K 2 CrO 4 Potassium Chromate

Copyright©2000 by Houghton Mifflin Company. All rights reserved. 12 Practice writing formulas for 1.Vanadium (V) fluoride 2.Dioxygen difluoride 3.Rubidium peroxide 4.Gallium oxide 5.Tetraphosphorus decaoxide 6.Niobium (V) oxide 7.Strontium peroxide 8.Titanium (IV) nitrate

Copyright©2000 by Houghton Mifflin Company. All rights reserved. 13 Practice writing formulas for 1.Vanadium (V) fluorideVF 5 2.Dioxygen difluorideO 2 F 2 3.Rubidium peroxideRb 2 O 2 4.Gallium oxideGa 2 O 3 5.Tetraphosphorus decaoxideP 4 O 10 6.Niobium (V) oxideNb 2 O 5 7.Strontium peroxideSrO 2 8.Titanium (IV) nitrateTi(NO 3 ) 4

Copyright©2000 by Houghton Mifflin Company. All rights reserved. 14 A flowchart for naming acids. An acid is best considered as one or more H+ ions attached to an anion.

Copyright©2000 by Houghton Mifflin Company. All rights reserved. 15 Name the following Acids HCl HI HCN HNO 3 H 2 SO 4 H 2 SO 3

Copyright©2000 by Houghton Mifflin Company. All rights reserved. 16 Name the following Acids HCl HI HCN HNO 3 H 2 SO 4 H 2 SO 3 Hydrochloric Acid Hydroiodic Acid Hydrocyanic Acid Nitric Acid Sulfuric Acid Sulfurous Acid

Copyright©2000 by Houghton Mifflin Company. All rights reserved. 17 Write Formulas for Hydrofluoric Acid Hydrosulfuric Acid Nitrous Acid Phosphoric Acid Acetic Acid

Copyright©2000 by Houghton Mifflin Company. All rights reserved. 18 Write Formulas for Hydrofluoric AcidHF Hydrosulfuric AcidH 2 S Nitrous AcidHNO 2 Phosphoric AcidH 3 PO 4 Acetic AcidHC 2 H 3 O 2

Copyright©2000 by Houghton Mifflin Company. All rights reserved. 19 Home Work Page 77 Problems #59-72 Blue