Transcript Slide 1

Objective
•I can write the
correct formula and
name for ionic
compounds
Ionic Bond –
The attraction between a positively charged
cation(s) and a negatively charged anion(s)
Compounds composed of two elements are
called binary compounds.
When writing the formula for a binary ionic
compound, the positive charge of the
cation must be equal to the negative
charge of the anion.
An ionic compound must be electrically
neutral.
For your notes: binary means two
• Most ions appear as monatomic ions.
• The charge for most monatomic ions is
related to their A Group number on the
Periodic Table.
• Every element will lose or gain electrons to
look like a noble gas – 8A group
1A
2A
Li+
3A
4A
5A
6A
7A
Be2+
N3-
O2-
F-
Na+
Mg2+ Al3+
P3-
S2-
Cl-
K+
Ca2+
As3-
Se2-
Br-
Rb+
Sr2+
Cs+
Ba2+
I-
8A
The charge signs are always dropped
The cation is usually written first.
Ex. K+ and Cl- combine in a one-to-one
ratio (one K for every Cl) = KCl
Ex. Ca2+ and Br- combine in a one-to-two
ratio (one Ca for every two Br) = CaBr2.
Crisscross method: the numerical charge of
each ion is crossed over and used as a
subscript for the other ion.
Example:
Fe3+
O2-
Crisscross method: the numerical charge of
each ion is crossed over and used as a
subscript for the other ion.
***The charge signs are always dropped***
Example:
Fe3+
O2-
Crisscross method: the numerical charge of
each ion is crossed over and used as a
subscript for the other ion.
***The charge signs are always dropped***
Example:
Fe2
O3
Crisscross method: the numerical charge of
each ion is crossed over and used as a
subscript for the other ion.
***The charge signs are always dropped***
Example:
Fe2
O3
Fe2O3
•
Practice on your own:
1. Mg2+ N32. K+
S2-
3. Sr2+
Cl-
4. Ba2+
O2-
•
Practice on your own:
1. Mg2+ N32. K+
S2-
3. Sr2+
Cl-
4. Ba2+
O2-
Mg3N2
•
Practice on your own:
1. Mg2+ N3-
Mg3N2
2. K+
S2-
K2S
3. Sr2+
Cl-
4. Ba2+
O2-
•
Practice on your own:
1. Mg2+ N3-
Mg3N2
2. K+
S2-
K2S
3. Sr2+
Cl-
SrCl2
4. Ba2+
O2-
•
Practice on your own:
1. Mg2+ N3-
Mg3N2
2. K+
S2-
K2S
3. Sr2+
Cl-
SrCl2
4. Ba2+
O2-
Ba2O2  BaO
Naming Cations:
the name of a cation is the same as the
name of the element.
Sodium atom (Na)  sodium ion (Na+)
Lithium atom (Li)  lithium ion (Li+)
Aluminum atom (Al)  aluminum ion (Al3+)
Naming Anions:
the name of an anion typically ends in –ide.
Sulfur atom (S) 
Chlorine atom (Cl) 
Fluorine atom (F) 
Naming Anions:
the name of an anion typically ends in –ide.
Sulfur atom (S)  sulfide anion (S2-)
Chlorine atom (Cl) 
Fluorine atom (F) 
Naming Anions:
the name of an anion typically ends in –ide.
Sulfur atom (S)  sulfide anion (S2-)
Chlorine atom (Cl)  chloride anion (Cl-)
Fluorine atom (F) 
Naming Anions:
the name of an anion typically ends in –ide.
Sulfur atom (S)  sulfide anion (S2-)
Chlorine atom (Cl)  chloride anion (Cl-)
Fluorine atom (F)  fluoride anion (F-)
•
Practice on your own:
1. Mg3N2
2. K2S
3. SrCl2
4. Ba2O2  BaO
•
Practice on your own:
1. Mg3N2
2. K2S
3. SrCl2
4. Ba2O2  BaO
Magnesium nitride
•
Practice on your own:
1. Mg3N2
Magnesium nitride
2. K2S
Potassium sulfide
3. SrCl2
4. Ba2O2  BaO
•
Practice on your own:
1. Mg3N2
Magnesium nitride
2. K2S
Potassium sulfide
3. SrCl2
Strontium chloride
4. Ba2O2  BaO
•
Practice on your own:
1. Mg3N2
Magnesium nitride
2. K2S
Potassium sulfide
3. SrCl2
Strontium chloride
4. Ba2O2  BaO
Barium oxide
Polyatomic Ions:
These are groups of atoms that behave as a unit
and carry a charge.
1. Most polyatomic anions end in –ite or –ate.
2. Only two polyatomic anions end in –ide,
hydroxide (OH)- and cyanide (CN)-
For your notes: poly means ‘many’
3. The most commonly occurring anions are
given the ending -ate.
4. The anion ending in –ite indicates one less
number of oxygen atoms in the anion.
N
Polyatomic
anions with
Nitrogen:
O
O
O
N
O
Nitrite = (NO2)-
O
Nitrate = (NO3)-
For your notes:
Memory aid: -Ite is lite (the least) -ate is heavy ,”ate a lot” (the higher)
4. Per- as a prefix usually indicates four
oxygen atoms
An Example: perchlorate (ClO4)-
Six Common Polyatomic Ions
to Memorize!
Name
Formula
Charge
hydroxide
OH
nitrate
NO3 -
chlorate
ClO3 -
carbonate
CO3 2-
-
sulfate
SO4
2-
phosphate
PO4
3-
Write the polyatomic ionic compound formulas
Ca2+
Nitrate (NO3)-
Mg2+
Nitrite
Li+
Sulfate (SO4)2-
(NO2)-
Write the polyatomic ionic compound formulas
Ca2+
Nitrate (NO3)-
Mg2+
Nitrite
Li+
Sulfate (SO4)2-
(NO2)-
Ca(NO3)2
Write the polyatomic ionic compound formulas
Ca2+
Nitrate (NO3)-
Mg2+
Nitrite
Li+
Sulfate (SO4)2-
(NO2)-
Ca(NO3)2
Mg(NO2)2
Write the polyatomic ionic compound formulas
Ca2+
Nitrate (NO3)-
Mg2+
Nitrite
Li+
Sulfate (SO4)2-
(NO2)-
Ca(NO3)2
Mg(NO2)2
Li2(SO4)
Naming Polyatomic Ionic Compounds
1) Simply name the polyatomic ion.
Polyatomic anions usually end in –ite or –ate.
Name the polyatomic ionic compounds
Nitrate: (NO3)-
Ca(NO3)2
Nitrite: (NO2)-
Mg(NO2)2
Sulfate: (SO4)2-
Li2(SO4)
Name the polyatomic ionic compounds
Nitrate: (NO3)-
Ca(NO3)2
Nitrite: (NO2)-
Mg(NO2)2
Sulfate: (SO4)2-
Li2(SO4)
Calcium Nitrate
Name the polyatomic ionic compounds
Nitrate: (NO3)-
Ca(NO3)2
Calcium Nitrate
Nitrite: (NO2)-
Mg(NO2)2
Magnesium Nitrite
Sulfate: (SO4)2-
Li2(SO4)
Name the polyatomic ionic compounds
Nitrate: (NO3)-
Ca(NO3)2
Calcium Nitrate
Nitrite: (NO2)-
Mg(NO2)2
Magnesium Nitrite
Sulfate: (SO4)2-
Li2(SO4)
Lithium Sulfate
Cations of Transition Metals
• Remember all metals form cations.
• Unlike the cations of group 1A, 2A and 3A metals,
many of the cations of group B, the transition metals,
have more than one common ionic charge.
• This also characteristic of Tin and Lead, the two
metals in group 4A
Cations of Transition Metals
• For example: Iron forms two common
cations:
– Fe2+ and Fe3+
• So, how can we distinguish these two
cations of iron?
– In the name of the cation, a roman numeral in
parenthesis indicates
of say….”
the charge.
Formula
Name the value
You
–Fe
When
say the ion
cation, you
include
2+ youIron(II)
“Iron
twoits
ion”
charge in the name
Fe3+
Iron(III) ion
“Iron three ion”
Practice – write the name or formula
Name
Formula
Copper(I) ion
Copper(II) ion
Manganese(II) ion
Co3+
Pb2+
Sr2+
Cu+
Practice – write the name or formula
Name
Formula
Copper(I) ion
Cu+
Copper(II) ion
Cu2+
Manganese(II) ion
Mn2+
Cobalt(III) ion
Co3+
Lead(II) ion
Pb2+
Strontium ion
Sr2+
Copper(I) ion
Cu+
Forming compounds with transition
metals
• Many transition metals form brightly
colored compounds that have been used
in making artist’s paints.
Forming compounds with transition
metals
Writing the formula when given the ions that combine
• Example: copper(II) and bromine
– step 1:Write the symbols for the ions
– step 2: Use the crisscross method
Forming compounds with transition
metals
Writing the formula when given the ions that combine
• Example: copper(II) and bromine
– step 1:Write the symbols for the ions
Cu2+
Br-
– step 2: Use the crisscross method
Cu2+ BrCuBr2
Forming compounds with transition
metals
Write the name when given the chemical formula.
• Example: CoF3
– step 1: identify the cation and anion:
• Cobalt is the cation
• Fluoride is the anion
– step 2: if the cation is a transition metal (d-block), uncrisscross to determine its charge
– step 3: Write the cation name with its charge in roman
numerals and name the anion.
Forming compounds with transition
metals
Write the name when given the chemical formula.
• Example:
CoF3
– step 1: identify the cation and anion:
• Cobalt is the cation
• Fluoride is the anion
– step 2: if the cation is a transition metal (d-block), uncrisscross to determine its charge
• Cobalt’s charge is +3
– step 3: Write the cation name with its charge in roman
numerals and name the anion.
cobalt(III)fluoride
Practice – write the name or formula
Name
Formula
Copper(I) Fluoride
Copper(II) Fluoride
Manganese(II) Phosphide
Iron(III) Oxide
PbCl2
SrF2
FeO
Practice – write the name or formula
Name
Formula
Copper(I) Fluoride
CuF
Copper(II) Fluoride
CuF2
Manganese(II) Phosphide
Mn3P2
Iron(III) Oxide
Fe2O3
Lead(II) Chloride
PbCl2
Strontium Fluoride
SrF2
Iron(II) Oxide
FeO
Objective
• I can write the name or
formula of a transition
metal cation
• I can write the name or
chemical formula of
transition metal ionic
compounds