Transcript Compounds

Ionic Compounds
Bonds
• Chemical bonds are __________ forces
• They act between atoms within a molecule
Why does bonding occur?
• Bonding occurs to maximize stability of
the atoms involved.
• More stable = LOWER potential energy
Bond types
• Dependent on the difference between the
__________________ of the elements
involved in bond
▫ Electronegativity
 Ability of an atom to ________________
 Highest found in _______________
 _________ are not ranked
Bond Types (cont)
• To Determine Type
▫ Subtract the electronegativities
▫ If difference is
 ______ – bond is non-polar covalent
 ______- bond is polar covalent
 Greater than 1.67- ______
Bonding is all about the electrons!
• Bond type tells us what will happen to the
electron(s)
• Octet rule will give us an idea of how
many electrons will be involved
▫ Have to look at __________________
▫ Remember most atoms are stable with ___
▫ Common exceptions
 H, He, Li, and Be can be stable with 2
 B is stable with 6
 Elements with d orbitals (can have more
than 8)
Valence electrons
Ionic bonding
• Ionic bonding involves the
______ of valence electrons.
• Creates _____
▫ Cation- + ion (___ electrons)
▫ Anion- - ion (____ electrons)
• Ions of opposite charges are
attracted to each other (the
attraction is the bond)
Na
F
Electron is transferred
Na
F
Charges
+1
Na
-1
F
Atoms are attracted to each other
+1
Na
F
-1
And each have 8 valence electrons
Ionic Compounds
• Will often form a _____
structure
• Formulas give the
___________ number
ratio between the ions
Formulas
• Elements in the compound are listed with the
number of atoms of each type listed as
___________
▫ For example, NaCl
 Has a ___ ratio of Na+ ions and Cl- ions
▫ CaI2
 Has a ___ ratio of Ca+2 ions to I- ions
Formulas (cont.)
• More complex formulas can have parenthesis
with a subscript on the outside
• The subscript on the outside applies to all
elements ___ the parenthesis
▫ For example, Al(NO3)3
 Has __ Al atom
 ___ N Atoms
 And ___ O atoms
Binary Compounds
• Compounds only containing ___________ of
elements
▫ For example





H20
FeI3
NaCl
Ag2S
CaBr2
Ionic Compounds: Binary
• Binary: Metal bonded with Nonmetal
▫ Type 1- Metal comes from Group ___________
▫ Type 2- Metal comes from Group _________
 Transition metals are multivalent (can take multiple
charges)
 Except Ag (___), Cd (___), and Zn (___)- treat
these like type 1
Base Name
• _______ is named
• Anion is named, but ending is changed to _____
Binary Compounds: Type 1
• Compound made from a metal from group 1, 2, Al, Ag, Cd, or Zn
with a nonmetal (ionic bond)
▫ For example: NaCl, BeF2, Al2O3, K2S
• Metal forms a cation
▫
▫
▫
▫
▫
▫
Group 1- ___
Group 2- ___
Al- ___
Ag- ___
Cd- ___
Zn- ___
▫
▫
▫
▫
Sometimes Group 14- ____
Group 15- ____
Group 16-____
Group 17- ____
• Nonmetal forms an anion
Creating Type 1 Formulas
• Steps
1. Determine the charge of the ion that each
element will form
2. Determine how many ions of each type will be
needed to make the overall charge of the
compound zero (neutral)…put each number as
subscripts after that element’s symbol
3. Make sure the formula is reduced to its simplest
form
Creating Type 1 Formulas (cont)
• For example,
▫ What is the formula for a compound made of
calcium and bromine?
BrCa2+
Br-
Naming Type 1 Compounds
• Base Name ________
▫ Metal is named first
▫ Make sure to change the ending of the anion to
-ide
▫ For example:
 NaCl is ___________
 CaBr2 is ____________
 Li2O is _____________
Binary Compounds: Type 2
• Compound made from a metal from group 3-12
(transition metals or multivalent metals) with a
nonmetal (ionic bond)
▫ For example: FeCl2, FeCl3, Cu2S3
• Metal forms a cation
▫ Charges vary from element to element
▫ Most of the transition elements can have several different
charges
• Nonmetal forms an anion
▫
▫
▫
▫
Sometimes Group 14- -4
Group 15- -3
Group 16- -2
Group 17- -1
Creating Type 2 Formulas
1. Determine the charge of the anion (the charge of
metal will be given to you)
2. Determine how many ions of each type will be
needed to make the overall charge of the
compound zero (neutral)…put each number as
subscripts after that element’s symbol
3. Make sure the formula is reduced to its simplest
form
Creating Type 2 Formulas (cont)
• For example,
▫ What is the formula for a compound made of iron
(+2) and chlorine?
Cl-
Fe2+
Cl-
Naming Type 2 Compounds
• Base Name + Roman numeral for charge of metal
▫ Metal is named first
▫ Make sure to change the ending of the anion to -ide
▫ After the name of the metal, the charge of the metal
needs to be put in Roman numerals in parenthesis
(because we can’t just look up the charge on the
periodic table)
▫ For example
 FeCl2 is ______________
 Fe2O3 is _____________
 CrS is _______________
Other Ionic Compounds: Polyatomic
Ions
• Polyatomic ions- two or more atoms combined that have
an overall charge (form an ion)
2CO32-
+
NH4+
Polyatomic Names
• 10 Polyatomic Names to memorize
• Others can be built off of those names
▫ Base is __________
▫ One less oxygen is ___________
• For example:
▫ NO3- is ______________
▫ NO2- is _____________
Compounds with Polyatomic Ions
• Can be
▫ Type 1 metal (groups 1, 2, Al, Ag, Cd, or Zn) cation
bonded with a polyatomic anion
 For example: Mg(NO3)2, Cs2SO4, Ca(IO3)2
▫ Type 2 metal (transition metal) cation bonded
with a polyatomic anion
 For example: NiSO3, Fe2(CO3)3
▫ Or, a polyatomic cation bonded with a nonmetal
(treat like a type 1)
 NH4Cl, (NH4)2O
▫ All of these are ionic bonds
Creating Formulas for Compounds with
Polyatomic Ions
1. Determine the charge of the cation and anion
o
o
o
Polyatomic ion- chart
Type 1 metal and nonmetals- determine charge from
group # on periodic table
Type 2 metals- charge will be given to you
2. Determine how many ions of each type will be needed
to make the overall charge of the compound zero
(neutral)…put each number as subscripts after that
element’s or polyatomic ion’s symbol
o
If a subscript is placed after a polyatomic ion, the ion
should be put in parenthesis with the subscript after it.
3. Make sure the formula is reduced to its simplest form
Creating Formulas for Compounds with
Polyatomic Ions (cont)
• For example,
▫ What is the formula for a compound made of
potassium and the polyatomic ion hydroxide?
Creating Formulas for Compounds with
Polyatomic Ions (cont)
• For example,
▫ What is the formula for a compound made of gold
(+2) and the polyatomic ion phosphate?
Creating Formulas for Compounds with
Polyatomic Ions (cont)
• For example,
▫ What is the formula for a compound made of the
polyatomic ion ammonium and bromide?
Naming Compounds with Polyatomic
Ions
• Compounds with
▫ Type I metals and a polyatomic anion (base name without –
ide)
 Same as before except polyatomic ion name is the second name
(do not change the ending to –ide)
 For example: LiC2H3O2 is lithium acetate
▫ Type II metals and a polyatomic anion (base name without
–ide but with Roman numeral)
 Same as before except polyatomic ion name is the second name
(do not change the ending to –ide)
 For example: Sn(ClO3)2 is tin (II) chlorate
▫ A polyatomic cation and a nonmetal (base name)
 Polyatomic ion name comes first, the second name is the name
of the nonmetal with the ending changed to –ide
 For example: NH4F is ammonium fluoride