Ionic Formulas. What are ions? Review: What’s the difference between monatomic and polyatomic...
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Transcript of Ionic Formulas. What are ions? Review: What’s the difference between monatomic and polyatomic...
Ionic Formulas
What are ions?
• Review: What’s the difference between monatomic and polyatomic ions?
Monatomic Ion – ion with only one element
Polyatomic Ion – ion with more than one element
WARNING!
• We’re going to start out with JUST MONATOMIC IONS.
• We’ll work on POLYATOMIC IONS later.
Ionic Compound
Ionic Compound – a compound in which positive and negative ions attract each other to keep matter together- Overall charge of the compound is neutral
Ionic Formula
• How do we represent an ionic compound?
Ionic Formula – Similar to a chemical formula, this shows what ions (AND how many of each ion) are in an ionic compound
Writing Ion PracticeLook at the ions and formulas listed below. Do you notice
any patterns?
Ions FormulaLi+ F- LiFNa+ Cl- NaClBe2+ O2- BeOMg2+ O2- MgOAl3+ N3- AlN
Ions FormulaLi+ O2- Li2O
Na+ N3- Na3N
Mg2+ F- MgF2
Al3+ Cl- AlCl3
Be2+ N3- Be3N2
Writing Formulas – Equal Charges
If the cation and anion charge are the same value:
Ions FormulaLi+ F- LiFNa+ Cl- NaClBe2+ O2- BeOMg2+ O2- MgOAl3+ N3- AlN
Drop the charges and write the elements
Cation first, then anion
Writing Formulas – Equal Charges
Example 1) Lithium Fluoride
Li+
F-
LiF
Writing Formulas – Equal Charges
Example 2) Magnesium Oxide
Mg2+
O2-
MgO
Writing Formulas – Different Charges
If the cation and anion charge are not equal,
1 cation and 1 anion will not form a neutral compound.
Ions FormulaLi+ O2- Li2O
Na+ N3- Na3N
Mg2+ F- MgF2
Al3+ Cl- AlCl3
Be2+ N3- Be3N2
Writing Ionic Formulas
STEP1) Write the cation
first, then the anion.
EXAMPLEAluminum Chloride
Al3+ Cl-
Writing Ionic Formulas
STEP2) Drop the + and –
(but NOT the numbers!!)
EXAMPLEAluminum Chloride
Al3 Cl1
Writing Ionic Formulas
STEP3) Cross the charges.
EXAMPLEAluminum Chloride
Al3 Cl1
Al1Cl3
Writing Ionic Formulas
STEP4) Drop any “1”.
EXAMPLEAluminum Chloride
Al1Cl3
AlCl3
Writing Ionic Formulas
STEP1) Write the cation
first, then the anion.
EXAMPLEBeryllium Nitride
Be2+ N3-
Writing Ionic Formulas
STEP2) Drop the + and –
(but NOT the numbers!!)
EXAMPLEBeryllium Nitride
Be2 N3
Writing Ionic Formulas
STEP3) Cross the charges.
EXAMPLEBeryllium Nitride
Be2 N3
Be3N2
Writing Ionic Formulas
STEP4) Drop any “1”.
EXAMPLEBeryllium Nitride
Be3N2
Be3N2
Writing Ionic Names
Rule: Cation is written as its element’s name.
Anion name ends in –ide.
**Sometimes we have to figure out the name from the formula.
Given the ionic formula, work backwards to figure out the ions.
Names – Example 1
CaBr2
Ca2+ Br-
Calcium Bromide
Names – Example 2
CoI3
Co3+ I-
Cobalt (III) Iodide
Names – Example 3
CuS
Must have the same charge:
Cu2+ S2-
Copper (II) Sulfide
Group Practice
• There are 11 stations around the room. Find them all, and write the ionic formula and name for each in your notebook.
• You will need to bring your Ion Chart with you, since some of the ions are written with NAMES, others with SYMBOLS
Group Practice - CheckStation Cation Anion Ionic
FormulaIonic Name
1 K+ O2-
2 Na+ Br-
3 Ca2+ Iodide
4 Calcium S2-
5 Al3+ Fluoride
6 Iron (III) Te2-
7 Ag+ P3-
Group Practice - CheckStation Cation Anion Ionic
FormulaIonic Name
8 Li3N
9 Ga2Se3
10 Cu2O
11 CuO
Group Practice - CheckStation Cation Anion Ionic
FormulaIonic Name
1 K+ O2- K2O Potassium Oxide
2 Na+ Br- NaBr Sodium Bromide
3 Ca2+ Iodide CaI2 Calcium Iodide
4 Calcium S2- CaS Calcium Sulfide
5 Al3+ Fluoride AlF3 Aluminum Fluoride
6 Iron (III) Te2- Fe2Te3 Iron (III) Telluride
7 Ag+ P3- Ag3P Silver Phosphide
Group Practice - CheckStation Cation Anion Ionic
FormulaIonic Name
8 Li+ N3- Li3N Lithium Nitride
9 Ga3+ Se2- Ga2Se3 Gallium Selenide
10 Cu+ O2- Cu2O Copper (I) Oxide
11 Cu2+ O2- CuO Copper (II) Oxide
Independent Practice
• Fill out the Monatomic Ions Practice