Chapter 6 Nomenclature of Inorganic Compounds

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Chapter 6Nomenclature of Inorganic Compounds

• Objectives
• Distinguish between common and systematic names
  of compounds
• Review differences between elements and ions
• Be able to write formula from names of compounds
• Understand binary compounds
• Name compounds containing polyatomic ions
• Name and recognize acids

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Common and Systematic Names

• Common Names
• Arbitrary
• Not based on chemical composition
• Historically associated with a physical or
  chemical property
• Not consistent among languages or disciplines
• Systematic names
• Identify the chemical composition
• Devised by IUPAC

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Elements and Ions

• Diatomic molecules
• 2 atoms of same element
• H2, O2, N2, F2, Cl2, Br2, I2
• Polyatomic
• 3 or more atoms of same element
• Sulfur (S8) and Phosphorus (P4)
• Ion
• Charged particle
• Positive (cation)
• Negative (anion)

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Elements and Ions

• Naming cations
• Same as element but add the word ion
• Potassium ion
• Naming anions
• Stem of the parent name with ending changed to
  ide
• Add the word ion
• Oxide ion
• Commonly formed ions figure 6.2 pg 107

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Writing Formulas from Names of Compounds

• Chemical compounds must have a net charge of zero
• Compare charges of ions formed from elements
• Trade charges and rewrite as subscript on
  opposite ion
• Write with lowest possible whole numbers

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Writing Formulas from Names of Compounds

• Write formulas for
• Sodium and chlorine
• Aluminum and oxygen

Na1
Cl1-
NaCl
Al2O3
Al3
O2-
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Writing Formulas from Names of Compounds

• Write formulas for the following
• Calcium chloride
• Calcium will form Ca2
• Chlorine will form Cl1-
• Formula is CaCl2
• Magnesium oxide
• Magnesium will form Mg2
• Oxygen will form O2-
• Formula is MgO

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Writing Formulas from Names of Compounds

• Barium phosphide
• Barium will form Ba2
• Phosphorus will form P3-
• Formula is Ba3P2
• Sodium sulfide
• Sodium will form Na
• Sulfur will form S2-
• Formula is Na2S

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Binary Compounds

• Contain only two different elements
• Often metal with nonmetal (binary ionic compound)

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Binary Ionic Compounds Containing a Metal Forming
Only One Type of Cation

• Name of cation is left the same
• Name of anion is changed (-ide)
• Write formulas for the following compounds
• Strontium chloride
• Strontium is Sr2 and Chlorine is Cl-
• Calcium sulfide
• Calcium is Ca2 and Sulfur is S2-

SrCl2
CaS
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Binary Ionic Compounds Containing a Metal That
Can Form Two or More Types of Cations

• Metals in the center of the periodic table
• Iron can be Fe2 or Fe3
• Stock System
• Use Roman Numeral to designate charge of cation
• Copper (II) Chloride is CuCl2
• Tin (IV) Oxide is SnO2
• -ous and ic endings are also sometimes used

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Binary Ionic Compounds Containing a Metal That
Can Form Two or More Types of Cations

• Write the name for each of the following
  compounds
• PbI2
• Fe2O3
• CuO
• TiF4

Lead (II) Iodide
Iron (III) Oxide
Copper (II) Oxide
Titanium (IV) Fluoride
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Binary Compounds Containing Two Nonmetals

• Not ionic bonds - Molecular (covalent)
• Different system of naming
• Element that occurs first in the series below is
  written and named first
• Si, B, P, H, C, S, I, Br, N, Cl, O, F
• Usually given to youfirst element listed always
  named first
• Second element retains ide ending

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Binary Compounds Containing Two Nonmetals

• Prefix is attached to each element to indicate
  the number of atoms of that element in the
  molecule
• Mono (1) never used for first element

Prefix Meaning Prefix Meaning
Mono 1 Hexa 6
Di 2 Hepta 7
Tri 3 Octa 8
Tetra 4 Nona 9
Penta 5 Deca 10
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Binary Compounds Containing Two Nonmetals

• Examples
• N2O is dinitrogen monoxide (drop o)
• S2F10 is disulfur decofluoride
• You try
• P2O5
• CBr4
• NH3

Diphosphorus pentoxide
Carbon tetrabromide
Nitrogen trihydride
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Acids Derived from Binary Compounds

• Hydrogen compounds form acids in water
• Write symbol of H first, then the rest
• Shows it is an acid
• Naming
• Take stem of nonmetal
• Add prefix hydro-
• Add suffix ic
• Add the word acid

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Acids Derived from Binary Compounds

• H2S
• Hydrogen sulfide (if not in water)
• Hydrosulfuric acid
• HCl
• Hydrogen chloride (if not in water)
• Hydrochloric acid

Figure 6.4 on page 115 VERY HELPFUL FOR NAMING
BINARY COMPOUNDS
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Naming Compounds ContainingPolyatomic Ions

• Polyatomic ion
• Must be able to recognize common polyatomic ions
• Table 6.6 (pg 116)

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Naming Compounds ContainingPolyatomic Ions

• Usually end in ate or ite (but not always)
• -ate indicates
• -ite indicates
• Nitrate is NO3-
• Nitrite is NO2-
• Hypo-
• (if more than two varieties)

ClO- hypochlorite ClO2- chlorite ClO3-
chlorate ClO4- hyperchlorate or
perchlorate
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Naming Compounds ContainingPolyatomic Ions

• Need to recognize polyatomic ions in Table 6.6
• Hydroxide (OH-)
• Cyanide (CN-)

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Naming Compounds ContainingPolyatomic Ions

• Naming follows binary compound rules

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Naming Acids

• Oxy-acids
• Inorganic compounds containing hydrogen, oxygen,
  and one other element
• Change ending of polyatomic ion
• Add the word acid

• HC2H3O2
• Hydrogen acetate ion
• Acetic acid

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Homework

• Questions 1,3,6
• Paired Exercises 7-25 odd
• Additional Exercise 34 36
• Remember Quiz next class ?