Ionic Compounds and Naming
Chapter 4.10,4.11 and 5
Combining Elements
When we begin combining elements we make compounds.
Two types◦Non-metal and metal◦Non-metal and non-metal
Each type has unique physical and chemical properties
Look at non-metal and metal in detail now and non-metal and non-metal later
Ionic compounds
A metal and a non-metal combination make an ionic compound◦Each element or polyatomic group is an ion◦What makes an ion?
An ion is a charged particle (positive or negative) Difference between protons and electrons in an
element◦Ca vs Ca+2 (Ca+2 has 2 less electrons than Ca)
The number of valence electrons determines the type of ion formed◦Trying to reach noble gas state
Lose or gain electrons to reach magic number 8◦Valence electrons are known by group number
Main group elements only These atoms follow a pattern down the column
Valence electrons vs charge
Practice
How many valence electrons do the following elements have?
What would their charge be?
◦K Mg Al C◦P O Br Ar
◦Do you see any pattern to the charges? Metals make positive ions (cations) Non-metals make negative electrons (anions)
Ionic Equations
We can write ions as ionic equations
K+1 can be written as K → K+1 + 1e-N-3 can be written as N + 3e- → N-3
Try these:◦Mg and O
Making ionic compounds
All ionic compounds are overall neutral; that is when you add up all the charges the sum is zero
NaCl is made with Na+1 and Cl-1MgO is made with Mg+2 and O-2
Na2O is made with 2 Na+1 and O-2
MgCl2 is made with Mg+2 and 2 Cl-1
Practice
Put the following elements together to make ionic compounds
Be and FLi and SBa and NK and AsCs and C
Transition metals
What about the elements in-between group II and III?◦Called transition metals because they can
make more than one positive charge◦On our tables you can tell by the small black
number above the symbol…..
Practice with transition metals
Cu II and SW IV and OPd II and NCr III and Si
Polyatomic Ions
Some ions are actually a group of elements combined together◦Can not be broken apart◦Act as one unit
These are known as polyatomic ions
◦See handout
Naming Binary Compounds
Naming Binary Compounds
We can easily name binary compounds both ionic and covalent (non-metals)
◦Non-metals and metals use type I and II
◦Non-metals and non-metals use type III
Naming Binary Ionic Compounds
Type I◦Metal bonded to non-metal◦Metal always listed and named first
No changes in the metal name◦Metals only make ONE ion (known as simple
metals)◦Anion is listed second
Use the root of the name and add –ide◦Hydrogen becomes hydride◦Halogens remove –ine and add –ide◦Oxide, nitride, sulfide
◦ NaCl is sodium chloride
Type II◦use transition metals
Cation is first again and anion is changed the same as type I
The difference is that we need to designate the charge of the transition metal with a Roman Number
USE THE ANION TO DETERMINE THE CHARGE OF THE CATION!!!
CuO◦Oxygen is -2◦The compound must be neutral◦So the copper (Cu) must be +2◦The compound is named copper II oxide
Practice
Name the following ionic compounds:
CaF AlCl3 MgI2
CuBr2 Al2O3 CrCl3
Fe2O3 FeO FeCl3
The number of atoms has no influence on the name for type I and II
Polyatomic Ions
Polyatomic ions just use their name
K2SO4 would be potassium sulfate
NH4NO3 would be ammonium nitrate
Co(NO2)2
(NH4)3N
Type III◦Non-metal to non-metals
NUMBER OF ATOMS IS IMPORTANT FOR TYPE III
Use prefixes to determine the number of atoms in the name
Same naming scheme as type I Use entire name for 1st element -ide for 2nd Add prefixes for multiple atoms
◦Note: mono- is never used on 1st element
Prefixes◦1 – mono◦2 – di◦3- tri◦4- tetra◦5- penta◦6- hexa◦7- hepta◦8- octa◦9- nona◦10- deca
Practice
CCl4 would be carbon tetrachlorideN2O2 would be dinitrogen dioxide
PCl5 P4O6
N2O5 SF6
CO NO2
Naming Acids
Acids are a special group of binary compounds and have their own naming rules.
All acids begin with H and are dissolved in water
Acids without oxygen◦Use root of anion and add –ic and acid◦HCl is hydrochloric acid
Acids with oxygen◦ -ite becomes –ous◦ -ate becomes –ic◦H2SO3 is sulfurous acid
◦H2SO4 is sulfuric acid
Practice
Name these acids
HF
HNO3
H3PO4
Reversing the process
Write the formulas from these names:
Nitric acidPotassium sulfideSodium carbonateDinitrogen pentoxide
Hydrates
Naming hydrates uses the Greek prefixes as in Type III naming.
First name the binary ionic compound, then the hydrate.
CuSO4.6H2O would be
◦copper (II) sulfate hexahydrate.
Writing word/chemical equations
Solid zinc metal and aqueous lead (II) nitrate react to form aqueous zinc nitrate and solid lead metal.