Names & Formulas of Ionic Compounds by gN4R51

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									  Names & Formulas of Ionic
  Compounds

 Ionic compounds are named using the
  names of the ions that compose them.

 To name an ionic compound:

   Cation name followed by anion name

 Learn the names and formulas of the ions
  in your syllabus.
   The following slides explain the
     systematic way that ions are named.
  Naming Cations
 Cations formed from metal ions have the
  same name as the metal.

    K+         potassium ion
    Ca2+       calcium ion
    Al3+       aluminum ion
  Naming Cations
 Cations with varying charges

  the charge of the specific cation is
   given by Roman numeral in parentheses
   after the name of the metal

     Fe2+      iron (II) ion
     Fe3+      iron (III) ion
     Cu+       copper (I) ion
     Cu2+      copper (II) ion
  Naming Cations
 One common polyatomic cation found in
  ionic compounds

     NH4+      ammonium ion


 Note: Compounds whose formulas start
  with NH4 are ionic even though they are
  composed only of non-metals.
Naming Anions

 Monoatomic anions

  drop the ending of the element’s name
  add “ide”

  N      nitrogen        O     oxygen

  N3-     nitride        O2-   oxide
  Naming Anions
 Some simple polyatomic anions use the
  “ide” ending as well

        OH-    hydroxide
        CN-    cyanide
        O22-   peroxide
   Naming Oxyanions
 Oxyanions (polyatomic anions containing
  oxygen) have names ending in:
   “ate”             most common
                      oxyanion
                      of the element

  “ite”              same charge, 1 less
                      oxygen

NO3-    nitrate       SO42-     sulfate
NO2-    nitrite       SO32-     sulfite
CO32-   carbonate     PO43-     phosphate
                      PO33-     phosphite
   Oxyanions (cont.)

 Some elements like the halogens can form
  more than two oxyanions:

  “per”  1 more O than the “ate” oxyanion
  “hypo” 1 less O than the “ite” oxyanion

  ClO4-     perchlorate
  ClO3-     chlorate
  ClO2-     chlorite
  ClO-      hypochlorite
  Oxyanions
 Anions derived by adding H+ to an
  oxyanion:

  add “hydrogen” or “dihydrogen” as
   prefix to oxyanion name

  CO32-      carbonate
  HCO3-      hydrogen carbonate
             (usually called bicarbonate)

  PO43-      phosphate
  H2 PO4-    dihydrogen phosphate
  Naming Ionic Compounds
 Name ionic compounds using cation name
  followed by anion name

 NaCl        sodium chloride
 CaBr2       calcium bromide
 NaClO       sodium hypochlorite
 Cu(NO3)2    copper (II) nitrate
  Naming Ionic Compounds
Example: Write the names of these ionic
compounds.

Na2O
FeCl3
(NH4)3PO4
KClO4
SnO2
Cu(NO3)2
  Writing Formulas from Names
 Given the name of a compound, you must
  be able to write its formula.
   Identify the symbol and charge for each
    ion.

  Determine the correct number of each
   ion needed to balance the charges
   (write an electrically neutral formula).
Writing Formulas from Names

Example: Write the empirical formula for
ammonium sulfate

ammonium      NH4+

sulfate       SO42-             (NH4)2SO4

                 NH4+
                        SO42-
                 NH4+
  Writing Formulas from Names
Example: Write the formulas for these ionic
compounds

  lithium chloride
  barium nitrate
  sodium perchlorate
  iron(III) oxide
  sodium hydrogen phosphate
  Lead (IV) sulfate
  Names & Formulas of Acids
 Acid: a substance whose molecules form
  H+ ions when dissolved in water
  HCl (aq)
  HCN (g)
  HClO3 (aq)

 Name of acid depends on:
  Type of acid
    Oxygen present or not
    Pure or aqueous
  Name of anion
  Names & Formulas of Acids
 Three naming systems for acids:

  Oxyanion-based acids (with oxygen)

  Acids with “ide” anions (no oxygen)
    aqueous solutions
    gases
  Oxyanion Based Acids
 If the acid contains oxygen, identify the
  anion and write its name

 Change the ending of the anion name:

  “ite”  “ous acid”
  “ate”  “ic acid”

HClO4      perchlorate  perchloric acid
HClO2      chlorite     chlorous acid
  Oxyanion Based Acids
 Naming acids derived from oxyanions of S
  and P:
   H2SO4 :
     oxyanion = sulfate
     Sulfic acid         Sulfuric acid

  H3PO4 :
    oxyanion = phosphate
    Phosphic acid     Phosphoric acid
  Acids Without Oxyanions
 If the acid does not contain oxygen and is
  dissolved in water (aq):

  hydro + (anion name minus “ide”) + “ic
                   acid”

  HCl (aq)      hydro + chloride + ic acid
                hydrochloric acid

     “Hydro” = no oxygen and (aq)
  Acids Without Oxyanions
 If the acid does not contain oxygen and is
  a gas (g):

  name the acid as an ionic compound:
    hydrogen followed by anion name


        HCl (g)      hydrogen chloride

    “Hydrogen” = no oxygen and (g)
   Naming Acids

 To name an acid:
   Does it have oxygen?
     Yes
       Write name of anion
       Change “ate” to “ic acid”
       Change “ite” to “ous acid”

  If no oxygen, is it (aq)?
     Yes
       Start with hydro
       Add the name of anion
       Change “ide” to “ic acid”
  Naming Acids
 If no oxygen, is it (g)?
   Yes
      Start with hydrogen
      Add the name of the anion
 Naming Acids
Example: Name the following acids.

  HNO3

  HBr (aq)

  H2S (g)
   Writing Formulas from Acid Names
 To write the formula of an acid starting with the
  name of the acid, first decide which category of
  acid it is:
   Oxyanion based
   No oxygen, (aq)      (begins with “hydro”)
   No oxygen, (g)       (begins with “hydrogen”)

 Write the formula for the anion (including
  charge).

 Add enough H+ ions to make a neutral
  compound.
    Writing Formulas from Acid Names

Example: Write the formula for perchloric acid.


Category: oxyanion containing acid


Anion: perchloric acid  perchlorate (ClO4-)

              H+       ClO4-


Formula:   HClO4
 Writing Formulas from Acid Names
Example: Write the formula for each of the
following acids.

   Phosphoric acid:

   Hydrobromic acid:

   Hydrogen cyanide:
   Naming Acids
 You must know the names and formulas for
  the following acids:

 HF (aq)           hydrofluoric acid
 HCl (aq)          hydrochloric acid
 HBr (aq)          hydrobromic acid
 HI (aq)           hydroiodic acid
 HClO4             perchloric acid
 HClO3             chloric acid
 H2SO4             sulfuric acid
 HNO3              nitric acid
   Naming Acids
 You must know the names and formulas for
  the following acids:

 H3PO4             phosphoric acid
 HC2H3O2           acetic acid
 H2CO3             carbonic acid
 H2S (g)           hydrogen sulfide
 HCN (g)           hydrogen cyanide
  Binary Molecular Compounds
 Binary molecular compound: compound
  composed of molecules with two different
  types of atoms

  Remember: Many molecular
   compounds are composed strictly of
   non-metals.

     SO2            N2O4
     H2O            PCl5
     P4O10     CO
      Binary Molecular Compounds
    The names of binary molecular
     compounds give both the type and
     number of each type of atom present.

    The general pattern for naming binary
     molecular compounds is:


prefix element name prefix element name with ide ending
      Binary Molecular Compounds

prefix element name prefix element name with ide ending


    The first element is named using the name
     of the element.
    The second element is named using the
     “ide” ending.
    Greek prefixes are used to indicate the
     number of each type of element present.
 Greek Prefixes
Prefix   Meaning
mono       1
di         2
                   You must know these!!
tri        3
tetra      4
penta      5   P4S10 =
hexa       6
               tetraphosphorus decasulfide
hepta      7
octa       8
nona       9
deca       10
  Binary Molecular Compounds
 Special conventions for using Greek
  prefixes:
   Mono is never used with the first
    element

  The “a” or “o” in the prefix is dropped if
   the name of the element begins with a
   vowel.

  CO:
    carbon monooxide
    carbon monoxide
  Binary Molecular Compounds
Example: Name the following
compounds.

 N2O4

 PCl5

 Cl2O7
  Binary Molecular Compounds
Example: Write the formulas for the
following compounds.

 tetraphosphorus decoxide

 sulfur trioxide

 disulfur dichloride
  Naming — Revisited
 Before you can correctly name a
  compound or write its formula, YOU MUST
  determine which type of compound it is:

  Ionic           starts with a metal or
                   NH4
  Acid            starts with H or Hn
  Binary
   Molecular       two non-metals

 THEN use the appropriate naming system
  or method to write the formula.
  Simple Organic Compounds
 Organic compounds:
  compounds that contain carbon and
    hydrogen, often in combination with
    oxygen or nitrogen.
   Simple Organic Compounds

 You must know the names and structural
  formulas of the following simple organic
  compounds:
   Methane
   Propane
   Methanol
   Ethanol
   Acetic acid
   Acetone
  Simple Organic Compounds
 Methane:      Methanol:
         H            H
       H C H        H C OH
         H             H
 Ethane:                    H   H
                Ethanol:
                      H      C   C OH
       H H            H      H
                             H
                             C   H
                                 OH
     H C C H        H C
       H H            H H
  HSimple Organic Compounds
                     H O
H C OH
  Propane:       H C C OH
  H                Acetone:
     H H H          H
                       H O H
  H C C C H
                    H C C C H
     H H H
  Acetic Acid:        H     H

    H O
  H C C OH
    H
  Common “Household” Chemicals
 You are responsible for knowing the names
  and formulas for the chemical present in:
    Water (H2O)
    Ammonia (NH3)
    Baking soda
      sodium bicarbonate
      NaHCO3
    Natural gas
      Methane
      CH4
    Vinegar
      Acetic acid
      HC2H3O2 (structure on previous slide)
  Common “Household” Chemicals
 You are responsible for knowing the names
  and formulas for the chemical present in:
    Table salt
      Sodium chloride
      NaCl
    Bleach
      Sodium hypochlorite
      NaClO
    Hydrogen peroxide
      H2O2
  Common “Household” Chemicals
 You are responsible for knowing the names
  and formulas for the chemical present in:
    Drinking alcohol     H H
      Ethanol          H C C OH
      C2H5OH             H H
                                H OH H
    Rubbing alcohol          H C C C H
                              H O
      Isopropyl alcohol
                           H CH H H
                                 C OH
                  H           H
    Nail polish remover        H O H
      Acetone                H C C C H
                                H    H

								
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