NOMENCLATURE IONIC BONDING Thursday - Day 3 Notes
Dec 16, 2015
NOMENCLATURE IONIC BONDING
Thursday - Day 3 Notes
VIDEO CLIP ON HOW ATOMS BOND: IONIC COMPOUNDS
Click the link below to watch the video:
http://www.nbclearn.com/portal/site/learn/chemistry-now/how-atoms-bond
Quick Review
_Ions_____ - atoms that have lost or gained one or more electrons. __cation___ – positively charged ion _____anion___ – negatively charged ion The charge on the ion is known as the
___oxidation number____ __Polyatomic ion____ – ion consisting of
two or more atoms
Practice - write the ion with the charge for the following elements
* Li * Ca * H
* Be * Si * K
* Al * S * O
* Na * Fr * N
* F * Cl * P
+
2+
3+
+
-
2+ +
+-4 +
+ 3-
2-
2-
- 3-
NOTES #2: Binary Ionic Chemical Names and Formulas
Ionic bonds are formed between a
metal and a nonmetal OR
cation + anion. The bond involves the transfer of electrons from
the metal to the nonmetal. The electron is transferred from the cation to the
anion so that both atoms have a complete valence shell (usually 8 electrons in valance).
The overall charge of ionic compounds must equal
zero.
NamingIonic Compounds
* First name the cation and then the anion. (metal) (nonmetal)
* Change the ending of the anion to –ide.Example:
•MgCl2 magnesium chloride
•Li2S _________________________Lithium sulfide
Practice
MgO _________________________
K3P ________________________ CsCl ________________________ Ba3N2 ________________________
Magnesium oxide
Potassium phosphide
Cesium chloride
Barium nitride
DRAWING Lewis Dot Structures for Ionic Compounds
• The overall charge on the compound must equal zero, that is, the number of electrons lost by one atom must equal the number of electrons gained by the other atom.
• The Lewis Structure (electron dot diagram) of each ion is used to construct the Lewis Structure (electron dot diagram) for the ionic compound.
The Lewis Dot structures show the location of the valence electrons after the electrons have been transferred.Examples: Lithium fluoride
• Lithium atom loses one electron to form the cation Li+• Fluorine atom gains one electron to form the anion F- • Lithium fluoride compound can be represented as
Remember the Octet rule….
DRAWING Lewis Dot Structures for Ionic Compounds
Draw the Lewis structure of Lithium oxide. What would be the chemical formula for this compound?
Writing Formulas for Binary Ionic Compounds
When given two ions, __________________ the charges and make them the ___________________.
Do NOT keep the +/- signs _______________ subscripts if possible
This means we must reduce the subscripts if they have a common denominator.
Example: Ca4F8
Balancesubscripts
Reduce
CaF2
Writing Formulas for Binary Ionic Compounds
Ex:a. Na+1 + Cl-1 NaCl (+1 + -1 = 0)
b. Mg+2 + O-2 MgO * (+2 + -2 = 0)
* Don’t write this Mg2O2 because it must be reduced.
**Sum of charges must equal zero.
A. Using Balanced charges Method: B. Using the Crisscross method:
Example: Li+1 O-2
Now, let’s use the name to write the chemical formula Name cation anion formula Lewis Dot Structure
Lithium oxide _______ _______ _____________Li+1 O-2 Li2O
Li+1
Important Facts about Ionic Compounds
• We use subscripts to represent the number of each ion.
Al2O3
2 Aluminum Ions and 3 Oxide Ions
A. Using Balanced charges Method: B. Using the Crisscross method:
Magnesium phosphide ______ _______ ____________
Name cation anion formula Lewis Dot Structure
Mg2+ and P3-
Mg2+
Mg2+
P3-
6+ 6- = 0
Mg2+ and P3-
Mg 3 S 2
Mg2+ P3- Mg3P2
For example 2…Change it from Magnesium sulfide to Magnesium phosphide
Homework: Page 9
For added help: watch this video
And use your periodic table!!!!
Notes 3: Binary Ionic Compounds with Transition Metals (Multivalent cations)
Multivalent Cations are found mostly in the group B elements. (the middle of the periodic table)
These elements are also known as the Transition metals.
If your cation is a transition metal, then you must specify the charge with a Roman numeral.
Example: Iron (III) Sulfide
Just like the compounds we looked at yesterday, the sum of charges must equal zero . and we can still use the Criss-cross method when writing the chemical formula.
Roman Numer
al
Charge
I +1II +2III +3IV +4V +5VI +6VII +7VIII +8
Writing & Naming Formulas with Roman Numerals Practice
Cu+ S2- Cu2S
Mn2+ O2- MnO
Sn4+ F- SnF4
I-Pb2+Lead II iodide
O2-Fe3+Iron III oxide
Pb4+Lead IV oxide
P3-Co3+Cobalt III phosphide
Naming Ionic Compounds with Roman Numerals
If there is a transition metal (B group element) present in the formula, you will need to include a roman numeral when you name the compound.
So, which metals DO NOT require a roman numeral?
Al3+, Zn2+, Cd2+ and Ag+
Writing Multivalent Compounds HOMEWORK
Complete page 11REMEMBER: How can you determine the charge or roman numeral?
You will have to work backwards.
And
Roman Numeral = Charge of the Metal
Polyatomic Ions
A polyatomic ion are groups of atoms that behave as one unit. They are treated like single ions in formulas, but use
parenthesis when more than one is used in a formula. NEVER change name or look of polyatomic. If you change the
subscripts for any part of the polyatomic, then it is no longer that same polyatomic ion.
Otherwise….use all the same rules for naming and writing compounds as with any other Binary Ionic compound.
EX: NH4+ is not the same as NH+
CO32- is not the same as CO2
2- or CO2-
Polyatomic Ion Practice
Formula Name
Al+3 CO3 -2
Ca+2 NO3 -1
K+1 ClO3 -1
Al2(CO3)3 Aluminum carbonate
Ca(NO3)2 Calcium nitrate
KClO3Potassium chlorate
Question: How would potassium chlorite be different?
K+1 ClO2 -1 KClO2
Name the following compounds
Ba(OH)2
CaSO4
(NH4)3P
Barium hydroxide
Calcium sulfate
Ammonium phosphide
Write the formula for the following compounds:
cation anion formula
Strontium phosphate ________ _________ ______________
Lithium acetate ________ _________ ______________
Sodium sulfate _________ _________ ______________
Sr2+
Formula Writing for Compounds
Tips for SuccessBefore writing any formula,
Identify the type of compound.Ionic Metal and a Nonmetal or PAIMolecular Only Nonmetals
For all ionic compounds, circle polyatomic ions.
Examples
iron(III) nitrate Fe(NO3)3
carbon tetrachloride CCl4sodium oxide Na2Obarium hydroxide Ba(OH)2
dinitrogen trioxide N2O3
ammonium carbonate(NH4)2CO3
cobalt(III) nitrite Co(NO2)3
I
I
I
M
I
I
M
Naming Ionic Compounds with Polyatomic Ions
When you name a compound with a polyatomic ion, the polyatomic ion keeps its name.
It is easy to identify a compound with a polyatomic ion because it will have more than 2 elements (more than 2 capital letters).
Tips for Success
Before naming ANY compound, Determine the type of compound. If the compound is molecular, remember use prefixes.
If the compound is ionic, answer the following questions.Does the metal need a roman numeral?
Does the compound have a polyatomic ion?
Examples
NaHCO3sodium hydrogen carbonate (NH4)2O ammonium oxide FeSO4 iron(II) sulfate AgC2H3O2 silver acetate Ni(NO3)2 nickel(II) nitrate ClO chlorine monoxide AuClO3 gold(I) chlorate
I
I
II
I
M
I
Monday Bell Ringer
Which of the following compounds represent trichlorine hexoxide? A. Cl3O6
B. ClO3
C. O3Cl6 Which of the following compounds
represent manganese (III) oxide? A. MgO B. Mn2O3
C. Mg2O3
Properties of Acids
CorrosiveSour TasteReact with Metals to Produce Hydrogen Gas (H+)
pH less than 7Can conduct electricityContain H+ ionsGenerally found as (aq) or aqueous
Binary Acids
Binary acids are made up of HYDROGEN + ANOTHER ELEMENT. Example: HCl (hydrogen + chlorine)
Example: H2S (hydrogen + sulfur)
Naming Binary Acids:
1. Prefix: hydro-
2. Element Name
3. –ic
4. Last word: “acid”
Ie: hydroelementic acid
In Class Examples: Naming Binary Acids
HCl hydrochloric acid
HF hydrofluoric acid
HBr hydrobromic acid
Ternary Acids
These acids contain a POLYATOMIC ION.
Also called oxy-acids.Example: H2SO3 = sulfurous acid
Naming Ternary Acids
1. Name the polyatomic ion. 2. Change PAI ending in –ate to –ic.
Example: sulfate sulfuric phosphate phosphoric
3. Change PAI ending in –ite to –ous. Example: sulfite sulfurous
phosphite phosphorous 4. Last word is “acid”.
In Class Examples of Naming Ternary Acids:
H2 SO4 sulfuric acid
H2 CO3 carbonic acid
HNO2 nitrous acid
H3PO4 phosphoric acid
Writing Acid Formulas
You do not have notes on this- we will practice in a minute!
Always begins with Hydrogen! Hydrogen = H+
You will then follow the same process as you would an IONIC compound! Example: hydrochloric acid = H+ and Cl- = HCl Example: sulfuric acid = H+ and SO4
2- = H2SO4
Writing Acid Formulas:
Tips:
1. Your first element is ALWAYS H+
2. Identify if it is a BINARY acid or TERNARY acid.
- begins with hydro- and ends in –ic? (1 element!)
- no hydro- prefix, or ends in –ous? (PAI!)
STOP: IN CLASS PRACTICE
I’ll make a SMART board notebook, you will probably want to do it on the overhead.
Exit Ticket will be the page in the notes titled “In Class Practice for Nomenclature of Acids.”
Darla just emailed out a homework that I’ll probably use!
Writing Formulas for Acids
Remember your patterns. Hydro-ic acid No oxygen X-ic acid -ate polyatomic ion X-ous acid - ite polyatomic ion
The positive ion is always H+.The sum of the charges of the ions must add up to zero.
Examples
hydroselenic acid H2Se
phosphoric acid H3PO4
nitrous acid HNO2
sulfurous acid H2SO3
dichromic acid H2Cr2O7
Keys to Success
Before naming ANY compound, Identify the type of compound.
Molecular? Ionic? Acid? If it is molecular, remember to use your prefixes.
If it is ionic, ask yourself.Does the metal need a roman numeral?Does it contain a polyatomic ion?
If it is an acid, which pattern does it follow?
Mixing It Up!
H2CrO4 chromic acid Na2SO3 sodium sulfite HF hydrofluoric acid P5O10 pentaphosphorus
decoxide Fe(C2H3O2)2 iron(II) acetate ZnCl2 zinc chloride H3PO3 phosphorous acid
A
I
A
MI
I
A
Keys to Success
Before writing the formula for ANY compound, Identify the type of compound.
Molecular? Ionic? Acid? If it is ionic, does it contain a polyatomic ion? If it is an acid, which pattern does it follow?No Oxygen?-ATE Polyatomic Ion?-ITE Polyatomic Ion?
Examples
barium phosphate Ba3(PO4)2
bromic acid HBrO3
ammonium dichromate (NH4)2 Cr2O7
iron(III) sulfide Fe2S3
dichlorine heptachloride Cl2O7
hydrosulfuric acid H2S
gold(III) chlorate Au(ClO3)3
I
A
I
I
M
A
I
-ate
No O
PUZZLE PIECE ACTIVITY ON WRITING FORMULAS FOR IONIC COMPOUNDS
•Work in pairs to assemble the various compounds.•Let’s try the first one together.• What is the compound formed between Mg and
F?Mg2+
Magnesium
F-
fluorideF-
fluoride
A perfectly assembled compound should be a square or a rectangle.
MetalMetal’sCharge
Nonmetal
Nonmetal’s Charge
Picture of Puzzle Pieces
Formula NameSum of Charges
Mg F+2 -1 MgF2magnesium
fluoride0