Honors Chemistry

1
Honors Chemistry

• The Language of Chemistry
• Chemical Names and Formulas

2
Chemical Formulas

• Significance of Chemical Formula-indicates the
  number and types of atoms in the molecule or
  formula unit
• C8H18

Subscript indicates that there are 8 carbon atoms
in a molecule
Subscript indicates that there are 18 hydrogen
atoms in a molecule
3
In ionic compounds

• The formula gives the simplest ratio between the
  positive and negative ions in the compound.
• What types of atoms and how many are present in
  each of these ionic compounds?
• MgCl2
• Al2(SO4)3

4
Monatomic Ions

• Ions formed from a single atom
• The ions formed are based on their electron
  configurations---they will lose or gain electrons
  to obtain a noble gas configuration.
• Not all main group elements easily form ions
  ---atoms of C and Si form covalent bonds
• Some elements form ions that do not achieve a
  noble gas configuration ---atoms of Sn and Pb
  form ions with at 2 charge

5
Ions of Transition Elements

• Elements from the d-block form 2, 3 or in a few
  cases, 1 and 4 cations.
• Many transition elements form two ions of
  different charges
• Examples Cu, Fe, Cr, V

6
Naming Monatomic Ions

• Cations - Simply use the elements name
• Na sodium ion
• Ca2 calcium ion
• Anions -
• Drop the ending of the elements name
• Add the ending -ide to the root name
• Example Fluorine Fluoride F-
• Nitrogen Nitride N3-
• Page 221 - List of Monatomic ions and charges

7
Binary Ionic Compounds

• Compounds composed of two elements
• Writing formulas
• Write the symbols for the ions with the cation
  first.
• The charges of the ions must cancel out and make
  the compound neutral so cross over the charges by
  using the absolute value of each ions charge as
  the subscripts for the other ions.
• Check the subscripts and divide to give the
  smallest possible whole- number ratio of ions.

8
Nomenclature for Binary Ionic Compounds

• Simply name the cation and then the anion.
• Examples
• Al2O3 aluminum oxide
• CaCl2 calcium chloride
• NaP3 sodium phosphide

9
Practice Binary Ionic Compounds

• Write the formula for the compound formed between
  the following elements and then name the
  compound.
• Potassium and iodine
• Magnesium and fluorine
• Sodium and sulfur
• Aluminum and oxygen
• Aluminum and nitrogen

10
Practice Binary Ionic Compounds

• Name the Binary compounds indicated by the
  following formulas
• AgCl
• ZnO
• CaBr2
• SrF2
• BaO
• CaCl2

11
Nomenclature Stock System

• Since some transition elements can form more than
  one ion, we use Roman Numerals to indicate the
  charge in the formula.
• Fe2 iron(II)
• Fe3 iron(III)
• Cu2 copper(II)
• Cu copper(1)
• Naming a compound
• CuCl2 copper(II) chloride
• FeO iron(II) oxide
• Fe2O3 iron(III) oxide

12
Practice Using the Stock System

• Write the formula and give the name for the
  compound formed between the ions
• Cu2 and Br-
• Pb2 and Cl-
• Sn2 and O2-
• Hg2 and S2-
• Sn2 and F-
• Fe3 and O2-

13
Compounds Containing Polyatomic Ions

• Ions formed by more than one atom joined together
• Most are negatively charged
• Most are oxyanions--containing oxygen
• page 226 - Polyatomic Ions
• You must memorize the names and charges on the
  handout.

14
Oxyanions

• -ite versus -ate
• the -ite form of the ion had one less than the
  -ate form of the ion
• NO3- nitrate NO2- nitrite
• SO42- sulfate SO32- sulfite

15
Oxyanions

• Hypochlorite ClO-
• Chlorite ClO2-
• Chlorate ClO3-
• Perchlorate ClO4-

16
Nomenclature Ionic Compounds with Polyatomics

• Named the same way as other binary ionic
  compounds
• AgNO3 silver nitrate
• AgNO2 sliver nitrite
• Ca3(PO4)2 calcium phosphate
• Note When multiples of a polyatomic ion are
  present in a compound, the formula for the
  polyatomic ion are enclosed in parantheses

17
Practice Ionic Compounds with polyatomic ions

• Write formulas for the following ionic compounds
• Lithium nitrate
• Copper (II) sulfate
• Sodium carbonate
• Calcium nitrite
• Potassium perchlorate
• Name the following compounds
• Ag2O
• Ca(OH)2
• KClO3
• NH4OH
• Fe2(CrO4)3
• KClO3

18
Nomenclature Molecular Compounds

• The element with the smaller group number usually
  goes first. The first element is given a prefix
  only if it contributes more than one atom to the
  compound.
• The second element is named by a prefix that
  indicate the number of atoms of that element and
  the ending -ide.
• The o or a at the end of the prefix is
  usually dropped when the word following the
  prefix begins with another vowel.

19
Greek Prefixes
Name the following binary molecular
compounds SO3 ICl3 PBr5 SF6 N2O5 Write the
formulas for the following compounds Carbon
tetrachloride Phosphorus trichloride Dinitrogen
trioxide Carbon monoxide
20
Acids

• Hydrochloric acid - HCl
• Hydrofluoric acid - HF
• Hydrobromic acid - HBr
• Hydroiodic acid - HI
• Phosphoric acid - H3PO4
• Sulfuric acid - H2SO4
• Nitric acid - HNO3
• Perchloric acid - HClO4
• Acetic acid - CH3COOH