Chemistry Nomenclature Binary Ionic Compounds. What are they made of? Binary Ionic Example sodium, Na + metal chlorine, Cl - non- metal metal.

Chemistry Nomenclature

Binary Ionic Compounds

What are they made of?

Binary

Ionic

Example sodium, Na+ metal chlorine, Cl- non-metal

metal ion + non-metal ion

2 elements

REMEMBER !

• Metals tend to Lose electrons and become positive ions (cations).

• Non-metals tend to gain electrons and become negative ions (anions).

Example 1: Sodium and Fluorine. Draw Bohr-Rutherford diagrams of both atoms.

Na F+ -

Electro-magnetic Force is created by the TRANSFER of electrons forming a BOND !

Crystal Lattice Structure • Each electron which Sodium atom lost, is

grabbed by Fluorine atom. • There same number of Na+ and F- ions,

their ratio is 1:1, but • ions do not form molecules. Instead, they

are tightly packed in crystals with alternative + and – ions.

Example 2 : Aluminum and Chlorine. Draw Lewis diagrams of both atoms

AlCl

Cl

Cl

Chemical Formula

• Ex 1: One Sodium for One Fluorine– NaF

• Ex2 : One Aluminum for Three Chlorine – NaCl3

• Subscript 3 in the formula indicates that it takes 3 Cl atoms to 1 Al atom.

• With the right subscript, the overall charge of the compound is zero.

Naming Ionic Bonds from Formula

1) Write name of metal

2) Write name of non-metal

3) Non-metal suffix = IDE

sodiumsodium chlorinesodium chloride

NaCl

Cations and Anions

Common Simple Cations and Anions

Cation Name Anion Name*

H 1+ hydrogen H 1- hydride Li 1+ lithium F 1- fluoride Na 1+ sodium Cl 1- chloride K 1+ potassium Br 1- bromide Cs 1+ cesium I 1- iodide Be 2+ beryllium O 2- oxide Mg 2+ magnesium S 2- sulfide Al 3+ aluminum Ag 1+ silver

*The root is given in color.

Zumdahl, Zumdahl, DeCoste, World of Chemistry 2002, page 86

Writing Chemical Formulas for Ionic Compounds.

Points to note:The metal ion/cation is always firstThe nonmetal ion/anion is always written secondSteps:1. Write the chemical symbols for each element (metal first)2. Write the ionic charge above each element 3. Criss-cross the NUMBERS (not the signs) and write them

as subscripts

Example: Aluminum Chloride

Step 1:

Step 2:

Step 3: 1 3

Step 4: AlCl3

Formula from Name: Criss-Cross Rule

Al Cl

Al Cl

3+ 1-

write out name with space

write symbols & charge of elements

criss-cross charges as subsrcipts

combine as formula unit(“1” is never shown)

Aluminum Chloride

Example: Aluminum Oxide

Step 1:

Step 2:

Step 3: 2 3

Step 4: Al O3

Criss-Cross Rule

Al O

Al O

3+ 2-

write out name with space

write symbols & charge of elements

criss-cross charges as subsrcipts

combine as formula unit

Aluminum Oxide

2

Example: Magnesium Oxide

Step 1:

Step 2:

Step 3: 2 2

Step 4: Mg2O2

Criss-Cross Rule

Mg O

Mg O

2+ 2-

Magnesium Oxide

Step 5: MgO(reduce subscripts to lowest ratio)

Ex. 1 Magnesium and Chlorine    

Total Charge Check: Ex.2 Calcium and Oxygen   

 Total Charge Check:

HINTS:• Criss-cross rule will help you to figure

out the right subscript in the compound formula

• Ignore subscript if it is 1• Subscripts do not have signs: it’s a

number of ions!• Final formula shall not indicate charge

on top• Reduce subscripts, go by lower terms

Naming Binary Compounds

Formula Name

1 BaO ____________________

2 ________________ sodium bromide

3 MgI2 ____________________

4 KCl ____________________

5 ________________ strontium fluoride

6 ________________ cesium fluoride

barium oxide

NaBr

magnesium iodide

potassium chloride

SrF2

CsF

Multivalent Binary CompoundsContaining a Metal (Variable Oxidation Number) and Non Metal

To name these compounds (stock system): 1. Write the name of the metal2. Followed by Roman numerals in parentheses to indicate the oxidation number of the metal3. Write the name of the nonmetal, with its ending replaced by the suffix –ide.

Examples IUPAC System

FeCl2 Iron (II) chloride

SnO Tin (II) oxide

FeCl3 Iron (III) chloride

SnO2 Tin (IV) oxide

Common Multivalent Cations

Ion IUPAC System Fe 3+ iron (III) Fe 2+ iron (II) Cu 2+ copper (II) Cu 1+ copper (I) Au 3+ gold (III) Au 1+ gold (I) Sn 4+ tin (IV) Sn 2+ tin (II) Pb 4+ lead (IV) Pb 2+ lead (II) Cr 3+ chromium (III) Cr 2+ chromium (II) Ni 3+ Nickel (III) Ni 2+ Nickel (II)

Zumdahl, Zumdahl, DeCoste, World of Chemistry 2002, page 90

Naming Binary CompoundsFormula Name

1 SnF4 ____________________

2 HgO ____________________

3 ________________ copper (II) fluoride

4 ________________ copper (I) sulfide

5 Cr2O3 ____________________

6 ________________ lead (IV) oxide

tin (IV) fluoride

PbO2

mercury (II) oxide

CuF2

Cu2S

chromium (III) oxide