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					   Naming Ionic Compounds
• NaF    -
• LiCl   -
• MgO    -
    Naming Ionic Compounds
• NaF- Sodium Ion and Fluoride ion
• LiCl- Lithium Ion and Chloride Ion
• MgO- Magnesium Ion and Oxide Ion
   Naming Ionic Compounds
• NaF    -   Sodium Fluoride
• LiCl   -   Lithium Chloride
• MgO    -   Magnesium Oxide
    More Practice
 Cd(OH)2            Na2SO4
 Cadmium         Sodium Sulfate
 Ca(ClO)2        Sodium Sulfite
Hypochlorite        KClO4
Silver Cyanide
Ions You Should Know
Properties of Molecular & Ionic Compounds
     Chemical Substances;
     Formulas and Names
• Naming simple compounds
        Chemical compounds are classified as
        organic or inorganic.
        Organic compounds are compounds
        that contain carbon combined with other
        elements, such as hydrogen, oxygen, and
        nitrogen; they do not contain metals.
        Inorganic compounds are compounds
        composed of elements other than carbon
        and usually contain at least one metal
Chemical Formulas; Molecular
  • Organic compounds
     An important class of molecular
     substances that contain carbon is the
     organic compounds.
     Organic compounds make up the majority
     of all known compounds.
     The simplest organic compounds are
     hydrocarbons, or compounds containing
     only hydrogen and carbon.
     Common examples include methane, CH4,
     ethane, C2H6, and propane, C3H8.
Naming Covalent Compounds
   A covalent compound as we said before is
   formed by sharing electrons between 2
   nonmetals or metalloids.
   These compounds are usually molecular
   and are named using a prefix system.
      When naming these compounds name the
      element further to the left (in the periodic
      table) first, then the one on the right.
Naming Covalent Compounds
  You name the first element using the exact
  element name.
  Name the second element by writing the root of
  the element’s name and add the suffix “–ide.”
  If there is more than one atom of any given
  element, you add the Greek prefix denoting
  how many atoms of that element are present.
  Table lists the Greek prefixes used.
      If only one atom of the second element is
      present it gets the prefix “mono”
Naming Covalent Compounds
   Here are some examples of prefix names for
   binary molecular compounds.
      PF5    phosphorus pentafluoride
      SO2 sulfur dioxide
      SF6    sulfur hexafluoride
      N2O4 dinitrogen tetroxide
      CO     carbon monoxide
      Naming Acids
Acids are traditionally defined as compounds
that could donate an H+; however, they are
acids only in the presence of water. In other
words before they enter the liquid they are
covalent compounds and they are NOT acids.
There are two main types of acids:
  Binary acids consist of a hydrogen ion and any
  single anion. For example, HCl is hydrochloric
  An oxoacid is an acid containing hydrogen,
  oxygen, and another element. An example is a
  HNO3, nitric acid. (see Figure 2.23)
               Naming Acids
• Binary Acids
  – Start with the prefix “Hydro” which represents the
    Hydrogen, followed it with the root of the name of the
    second element and append the ending –oic acid.
• Oxoacids
  – Use the root of the “E” element if the ion taking part in
    the acid had an ending in –ate to the root append the
    ending –ic acid, if it ends on –ite then append the
    ending –ous acid. If the ion had a prefix use the same
              Naming Acids
• Examples:
  –   HCl(g) Hydrogen Chloride
  –   HCl(aq) HydroChloric Acid
  –   H2S(g) Dihydrogen Sulfide
  –   H2S(aq) HydroSulfic Acid
  –   H3PO4(aq) Phosphoric Acid
  –   HClO4(aq) Perchloric Acid
  –   HClO(aq) Hypochlorous Acid
     Ionic Compounds Formulas
• How do we know how many atoms of each ion we need?
   – A simple crossing of the charges can answer that question about
     90% of the time.
       • Example: Mg2+ and PO43-


   Check the charges… 3 x (+2) = +6
                            2 x (-3) = -6
   – When they combined they cancel to yield a neutral
    Ionic Compounds Formulas
• The crossing technique does not work if the
  magnitude of the charges is the same
• Example: Mg2+ and CO32-

     This is incorrect since we want the lowest
      ratio possible which is 1:1 to yield MgCO3
  Ionic Compounds Properties
• Ionic compounds have properties completely
  different from their component elements.
  – Example: Table Salt (NaCl)
     • Sodium (Na) in the presence of water reacts violently heating
       up the water and producing hydrogen if the temperature of the
       water is high enough the hydrogen can ignite explosively.
     • Chloride (Cl) Green poisonous and corrosive gas. If inhaled
       will destroy the nasal passages then dissolve in the stomach
       producing high concentration of hydrochloric acid which will
       destroy the stomach lining producing ulcers.
     • Salt (NaCl) posses none of the properties mentioned above.
                 Ionic Structure

•Ions form a 3-D lattice.
•The coulombic (electrostatic)
attraction is so high that in
order to separate one ion from
the lattice requires a lot of
energy (DHlatt).
•The lattice energy depends
on charge and size of the ions.
                  Lattice Energy
• Since the lattice energy is an electrostatic interaction the
  more separated the charges are the weaker the interaction
   – Bigger ions have lower lattice energies
• The higher the charge of the ions the stronger they will
  attract ions of the opposite charge.
                                           DH latt 
• When size and charge point to opposite trends the charge
  will outweigh the size.
   – From smallest atom to biggest atom there is only 1.7x factor. From
     a +1 to +2 that is already a 2x factor.
 Properties of Ionic Substances
• Dues to the charged interaction a blow to a
  crystal leads to the possibility of splitting
  the crystal since we will force like charged
  particles to interact.
• Ionic compounds have high melting/boiling
  points since in order to move the ions from
  their respective spots it will require
  breaking the lattice.
           Ionic Solutions
• However, if we do melt an ionic compound
  it will be able to conduct current.
• When ionic compounds are placed in a
  solvent the produced solution conducts
  electricity. The higher the number of ions
  the higher the conductivity.
• More when we cover chapter 4.
  Naming Hydrates
A hydrate is a compound that contains
water molecules weakly bound in its
Hydrates are named from the anhydrous
(dry) compound, followed by the word
“hydrate” with a Greek prefix to indicate
the number of water molecules per formula
unit of the compound.
For example, CuSO4. 5H2O is known as
copper(II)sulfate pentahydrate. (see Figure
     Determining Chemical
• Determining both empirical and
  molecular formulas of a compound
  from the percent composition.
   The percent composition of a compound leads
   directly to its empirical formula.
   An empirical formula (or simplest formula)
   for a compound is the formula of the substance
   written with the smallest integer (whole
   number) subscripts.
     Determining Chemical
• The percent composition of a compound is the
  mass percentage of each element in the compound.

  We define the mass percentage of “A” as the
  parts of “A” per hundred parts of the total, by
  mass. That is,
              mass of " A" in whole
mass % " A"                         100%
               mass of the whole
     Mass Percentages from
• Let’s calculate the percent composition of
  butane, C4H10.
    First, we need the molecular mass of C4H10.
     4 carbons @ 12.0 amu/atom  48.0 amu
  10 hydrogens @ 1.00 amu/atom  10.0 amu
      1 molecule of C4 H10  58.0 amu
    Now, we can calculate the percents.
   % C  58.0 amu total  100%  82.8%C
          48.0 amu C

   % H  58.0 amu total  100%  17.2%H
          10.0 amu H
    Determining Chemical
• Determining the empirical formula
  from the percent composition.
   Benzoic acid is a white, crystalline powder used as a
   food preservative. The compound contains 68.8% C,
   5.0% H, and 26.2% O by mass. What is its empirical
   In other words, give the smallest whole-number ratio
   of the subscripts in the formula

                        Cx HyOz
     Determining Chemical
• Determining the empirical formula
  from the percent composition.
   For the purposes of this calculation and making
   calculations simpler, we will assume we have 100.0
   grams of sample benzoic acid.
   Then the percentage of each element equals the mass
   of each element in the sample.
   Since x, y, and z in our formula represent mole-mole
   ratios, we must first convert these masses to moles.
           Determining Chemical
      Determining the empirical formula from
      the percent composition.
         Our 100.0 grams of benzoic acid would contain:
                         1 mol C
              68.8 g C            5.73( 3) mol C
                          12.0 g
                          1 mol H
                5.0 g C             5.0 mol H
                            1.0 g
                          1 mol O
               26.2 g O           1.63( 7 )mol O
                           16.0 g
This isn’t quite a whole number ratio, but if we divide each number by
         the smallest of the three, a better ratio might emerge.
          Determining Chemical
    Determining the empirical formula from
    the percent composition.
       Our 100.0 grams of benzoic acid would contain:
                5.73 mol C  1.63(7)  3.50

                 5.0 mol H  1.63(7)  3.0

              1.63(7) mol O  1.63(7)  1.00

now it’s not too difficult to see that the smallest whole number ratio
            is 7:6:2. The empirical formula is C7H6O2 .
     Determining Chemical
• Determining the “true” molecular
  formula from the empirical formula.
   An empirical formula gives only the smallest whole-
   number ratio of atoms in a formula.
   The “true” molecular formula could be a multiple
   of the empirical formula (since both would have the
   same percent composition).
   To determine the “true” molecular formula, we must
   know the “true” molecular weight of the
   Determining Chemical
• Determining the “true” molecular
  formula from the empirical formula.
   For example, suppose the empirical formula of a
   compound is CH2O and its “true” molecular weight
   is 60.0 g/mol.
   The molar weight of the empirical formula (the
   “empirical weight”) is only 30.0 g/mol.
   This would imply that the “true” molecular formula
   is actually the empirical formula doubled 2(CH2O) or

Molecular and structural formulas
     and molecular models.

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A model of a portion of a Sodium Chloride crystal.

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Common Ions of the transition metals

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List of Polyatomic Ions

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Greek Prefixes for Covalent
Compounds Nomenclature

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Making and Acid

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Molecular model of nitric acid.

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Figure 2.24: Copper (II) sulfate.
Photo courtesy of James Scherer.

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Naming Flow Chart

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Naming Flow Chart II

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Naming Acids Flow Chart

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Jun Wang Jun Wang Dr
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