More Ionic Bonding

Ionic bonding involves the electrical attraction of a cation (+) and an anion (-).

Charges and amounts of atoms balance to become a neutral compound.

NaNaNaNa22SS

NaNaSS+ SS

-22Na2Na+1+1 +

OXIDATION Process of an element becoming more POSITIVE. How does element oxidize?

By losing electrons

Example: Na0 Na+1 + 1e-

The ionic charge of Na (0 or +1) can also be called its oxidation number.

REDUCTION Process of an element becoming more NEGATIVE.

How does element reduce?

By Gaining electrons

Example: S0 + 2e- S-2

What’s the oxidation number for S?-2

Parts of an Equation: Putting it all together

NaNa22SSSS-22Na2Na+1+1 +

REACTANTS OXIDATION NUMBER

PRODUCTS COEFFICIENT

SUBSCRIPT

*Cation is always written first!

*Atoms combine in simplest whole number ratios to make their charges zero.

Example:

PRACTICE1. Write oxidation / reduction equations for

Potassium and Oxygen.

K0 K+1 + 1e- (oxidation)

O0 + 2e- O-2 (reduction)

2. Write the combined equation for potassium and oxygen when they form an ionic bond.

2 K+1 + O-2 K2O

Na + F [Na]+ + [ F ]-

Remember this?

Lewis Structures in an equation!

Brackets needed for IONS !!!!!

Ions can get a bit more complex…….

A group of atoms that bond together to form a larger charged particle.

This many atom particle acts as ONE and bonds with other particles to cancel out all charges!

Formula Charge Name

SO4-2 2- sulfate

SO3-2 2- sulfite

NO3-1 1- nitrate

NO2-1 1- nitrite

OH-1 1- hydroxide

NH4+1 1+ ammonium

PO4-3 3- phosphate

C2H3O2-1 1- acetate

CN-1 1- cyanide

Lewis Structures can be drawn for Polyatomic Ions, also:

The making of Sodium Phosphate:

3Na+1 + PO4-3 Na3PO4

Why are 3 sodium ions required ?

To balance the -3 charge of the phosphate

The making of Calcium Acetate

Ca+2 + 2C2H3O2-1 Ca(C2H3O2)2

When multiple numbers of polyatomic ions are needed to cancel out charges, they are put in parentheses.

PRACTICE

Write balanced equations and formulas for the following compounds:

Aluminum Hydroxide Ammonium Nitride

Calcium Sulfite

Barium Cyanide

Al+3 + 3OH-1 Al (OH)3

3NH4+1 + N-3 (NH4)3N

Ca+2 + SO3-2 Ca2(SO3)2 CaSO3

Ba+2 + 2CN-1 Ba(CN)2