Ionic Compounds

Ionic Compounds

ReviewWhat is an ion? An Ion is a charged atom or a

particle. What is a cation?A Cation is a + charged ion. What is an anion? An Anion is a – charged ion.

Finding the Charge of an Ion Group 1 metal make a +1 ion because it

has 1 e- in its valence shell and will lose it Group 2 metal make +2 ion because it has

2 e- in its valence shell and will lose them Group 13 METALS make +3 ions because it

has 3 e- in its valence shell Group 17 are nonmetals and make a -1

charge because it will accepts an e- to complete the valence shell

Group 16 are nonmetals and make a -2 charge accept two e- to complete the valence shell

Other Ion ChargesTransitional metals typically

make various positive chargesie. Pb2+ and Pb4+ , Fe2+ and Fe4+

Metals always form positively charge ions, nonmetals always form negatively charged ions

How does the size of an ion relate to the size of the parent atom?

Table of the size of an ion compared to its parent element on p411

Positive ions (Cations) are smaller than parent atom

Negative ions (anions) are larger than parent atom

Writing Formula for Ionic Compounds An ionic Compound is a compound

between a metal and a nonmetal Rules to follows for Writing ionic

Compounds1. Chemical compounds must have a net charge of zero2. Both + ions and – ions must be present3. The # charge of cations = the # charge of anions

Examples For Writing Ionic Compounds Na+ + Cl- NaCl Charge +1 -1 0 *Atoms don’t spontaneously lose e-. The

gain or loss is always paired. One atom loses the e- while another atom simultaneously gain the e-.

Mg2+ + Cl- MgCl2 Charge 2+ -1 0 Li+ + N3- Li3N Charge +1 3- 0

PracticeWrite the ionic Compound for the

following element combinations.1. Calcium and Chloride2. Sodium and Sulfur3. Calcium and Phosphorous4. Potassium and Iodine5. Magnesium and Nitrogen6. Aluminum and Oxygen

Naming CompoundsBinary Ionic Compounds are formed when a metal (cation) and a nonmetal (anion) form a compound.Two types of cations

Type I (simple)Always contain the

same chargeGroup 1, Group 2,

Group 13, and silver

Type II Metals can form two

or more different charges

Most Transitional Metals

Rules for Naming Type I Ionic Compounds  The cation is named first and the

anion is named secondThe simple cation takes its name

from the element.The simple anion takes the first part

of its name from the element and adds the root

–ide to the end.

Practice Naming Name each of these compounds. What

is the charge on each ion? How many cations are in the compound? How many anions are in each compound?

1. KCl 4. Al2S3

2. BaH2 5. MgI23. AlCl3 6. CaBr2

Rules for Naming Type II Ionic Compounds Some Cations can form multiple charges. ie. Pb2+ and Pb4+, Cr2+ and Cr2+ and Cr3+, Fe2+

and Fe3+, Au+ and Au3+

Chemist decided to use roman numerals to specify charge.

Ie. FeCl2 = Iron (II) Chloride FeCl3 = Iron (III) Chloride The old way of naming these compounds was to

use the ending –ous for the lower charger and –ic for the higher charge.

Ie. FeCl2 = Ferrous Chloride FeCl3 = Ferric Chloride

Distinguish Type I and Type II Cations Group I and Group 2 metals are always

Type I cations. Transitional Metals almost always are

Type II cations. Metals that form only one cation do not

need to be identified with a Roman Numeral.

Practice naming Type II Cations Write the name of each compound, the

charge of each element, the number of cations, and the number of anions, and the molecular mass.

CoCl3 MnO2

SnBr4 HgO CuCl PbS

Finding the Molecular Weight Also known as Molar

mass or Formula Weight

For Na+ + Cl- NaCl 1 mol Na+ = 22.99g

Na+

1 mol Cl- = 35.45g Cl-

1 mol of NaCl = 58.44g NaCl

For Iron (II) Oxide = Fe2O3

1 mol of Fe = 55.85g Fe

1mol of O = 16.00g O

1 mol of Fe2O3 = 159.70g of Fe2O3