Ionic Compounds

Ion formation•Octet rule- atoms want a full valence shell

▫ _____ valence electrons for most atoms▫ ____ and atoms that become isoelectronic with __ are

satisfied with ____ valence electrons▫ H can be satisfied with ___ or ___

•_____________▫ Low electronegativities and ionization energies ▫ Electrons are __________ until octet rule is satisfied (more

complicated in the transition metals)•______________

▫ High electronegativities and ionization energies ▫ Electrons are ________ until octet rule is satisfied

Valence electrons

Ions•An atom with a _____________

▫Imbalance of _________ and _________▫_____ or ______ electrons

•Two Types ▫Cation- __ charge because electrons are __

Cation with a common charge Multivalent cation Polyatomic cation

▫Anion- _ charge because electrons are ____ Anion with a common charge Polyatomic anion

Cations with a Common Charge

•Atoms that predictably form a cation with a certain charge

•Group 1 elements- form cations with __ charge

•Group 2 elements- form cations with ___ charge

•Al- forms cations with a ___ charge•Some of the other metals will also only

form one common ion

Multivalent Cations•Atoms that form multiple types of

cations

•All other metals not on the common cation list

Polyatomic Cations•Cation made up of multiple atoms

bonded together

•You only memorized one

NH4+

+

Naming Cations•Cations with a common charge

▫ “Element name” ion For example

Na+ is _____________ Ca+2 is _____________

•Multivalent cations▫ “Element name” (Roman numeral for charge) ion

For example Fe+2 is _____________ Fe+3 is _____________

•Polyatomic cations▫ “Polyatomic name” ion

NH4+ is _______________

Anions with a Common Charge

•Atoms that predictably form a anion with a certain charge

•Group 17 non-metals- form anions with __ charge•Group 16 non-metals- form anions with __ charge•Group 15 non-metals- forms anions with a ___

charge•Sometime Group 14 non-metals form anions with

a ____ charge

Polyatomic Anions

•Anion made up of multiple atoms bonded together

•You memorized 10, but by learning a set of rules you know more than 10.

•For polyatomics with oxygen ending with –ate▫Add one more oxygen, name is _________▫Take away one oxygen, name is ________▫Take away two oxygens, name is ________

CO32

-

2-

Polyatomic Anions (cont)• For example:

▫ You memorized ClO3- is chlorate

This ion has one chlorine and three oxygen atoms with a negative one charge

▫ ClO4- is _____________

This ion has one chlorine and four oxygen atoms (one more than the –ate ion) with a negative one charge

▫ ClO2- is ____________

This ion has one chlorine and two oxygen atoms (one less than the –ate ion) with a negative one charge

▫ ClO- is _____________ This ion has one chlorine and one oxygen atom (two less than

the –ate ion) with a negative one charge

Naming Anions•Anions with a common charge

▫ “Element name with ending changed to -ide” ion For example

Cl- is ____________ O-2 is ____________

•Polyatomic anions▫ “Polyatomic name” ion

For example CO3

-2 is ___________ NO3

- is ___________ NO2

- is ___________

Ionic bonding•Ions of opposite charges are attracted to each other

•This attraction is a chemical bond

F

Na

Electron is transferred

Na F

Charges

Na F+1 -1

Atoms are attracted to each other

Na F+1 -1

And each have 8 valence electrons

Bonds

•Chemical bonds are _______________

•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

Ionic Compounds

•Will often form a crystal structure

•Can be identified by name or formula▫ If given one, you can find the

other▫ Formulas give the smallest

whole number ratio between the ions

Naming Ionic Compounds

•Determine the name of the cation and anion involved in the ionic bond

•Name both (cation before anion) leaving off the “ion”▫ For example

An ionic compound between a magnesium ion and a fluoride ion would be ________________

An ionic compound between a copper (I) ion and a phosphate ion would be _________________

Formulas•Elements in the compound are listed

with the number of atoms of each type listed as subscripts▫For example, NaCl

Has a 1:1 ratio of sodium ions to chloride ions

▫CaI2

Has a 1:2 ratio of calcium ions to iodide ions

Formulas (cont.)

•Formulas with polyatomic ions can have parenthesis with a subscript on the outside

•The subscript on the outside denotes how many polyatomic ions are there ▫For example, Al(NO3)3

Has a 1:3 ratio of aluminum ions to nitrate ions

Switching Between Names and Formulas

•Name to Formula▫ Identify the symbol and charge of the anion

and the cation▫ Determine how many of cations and anions

are needed to balance the charges to neutral▫ Write the formula (cation first) with

subscripts denoting how many are needed of each ion Remember to put polyatomic ions in

parenthesis if adding a subscript to them

Switching Between Names and FormulasName to Formula example

▫What is the formula for calcium bromide?

Switching Between Names and FormulasName to Formula example

▫What is the formula for iron (II) chloride?

Switching Between Names and FormulasName to Formula example

▫What is the formula for potassium hydroxide?

Switching Between Names and Formulas•Name to Formula example

▫What is the formula for gold (II) phosphate?

Switching Between Names and Formulas•Name to Formula example

▫What is the formula for ammonium bromide?

Switching Between Names and Formulas

•Formula to name▫ Identify the name of the cation and anion in

the formula Remember multivalent cations need a Roman

numeral as part of their name. You will have to determine the charge from the formula clues.

▫ Name the compound

Switching Between Names and Formulas

•Formula to name examples▫ LiBr

▫ NiO