WRITING FORMULAS AND NAMING COMPOUNDS

Binary Compounds

Made up of only 2 elements Two types of Binary Compounds

1. Ionic Compounds- metal and nonmetal

Ex: NaCl, MgBr2, K2O

2. Covalent Compounds- 2 nonmetals Ex: CO2, H2O, SO3

Ionic or Covalent?

1. NO2

covalent2. P2O4

covalent3. Fe2O3

ionic4. CaF2

ionic

Covalent Compounds

NAMING A. Use prefixes to indicate the number of

atoms of each element mono-1 hexa-6 di-2 hepta-7 tri-3 octa-8 tetra-4 nona-9 penta-5 deca-10

B. Name the first element. If you have only one atom of the first element, do NOT use the prefix mono.

C. Name the second element with prefixes. Change the ending to “ide”.

Name the following:

1. CO2

carbon dioxide

2. SO3

sulfur trioxide

3. N2O4

dinitrogen tetroxide

4. CCl4 carbon tetrachloride

5. H2O

dihydrogen monoxide

Write the formula

1. phosphorus trichloride PCl32. nitrogen dioxide NO2

3. sulfur hexabromide SBr6

4. diphosphorus pentoxide P2O5

Ionic Compounds

NAMINGA. Name the first element (metal)

B. Name the second element (nonmetal) and change the ending to “ide”

C. NO PREFIXES!!!

Name the following:

1. NaCl

sodium chloride

2. CaF2

calcium fluoride

3. Ag2O

silver oxide

4. AlBr3

aluminum bromide

5. ZnS

zinc sulfide

Writing Formulas

Ionic compounds are composed of a positive ion called a cation and a negative ion called an anion.

A. Write the metal ion first. (+ ion: cation)

B. Write the nonmetal last. (- ion: anion)

C. Balance the charges! Charges must add up to zero to form a neutral compound.

How to determine the chargeYou can look at the position of the element

on the periodic table to determine the charge of the element when it forms an ion.

There is a difference between a neutral element (K) and an ion (K+).

Using the Periodic Table

Writing Formulas

1. sodium chloride Na+ Cl-

NaCl2. calcium chloride Ca+2 Cl-

Cl-

CaCl2

Writing Formulas

3. aluminum chloride Al+3 Cl-

Cl-

Cl-

AlCl3

Writing Formulas

4. potassium bromide K+ Br-

KBr5. potassium oxide K+ O-2

K+

K2O

Writing Formulas

6. aluminum oxide Al+3 O-2

Al+3 O-2

O-2

Al2O3

Review

Covalent compounds are made up of nonmetals only.

Use prefixes in the names of covalent compounds.

Covalent compounds do not have charges! Ionic compounds are made up of a metal and a

nonmetal. Balance the charges when you write a formula

for ionic compounds. Never use prefixes in the names of ionic

compounds!

Ionic Compounds with Roman Numerals

The roman numeral gives the charge of the metal ion.

Ex: Fe(II) Fe+2 Fe(III) Fe+3 Transition metals need roman numerals

in the name. Pb and Sn need roman numerals

because they have charges of +2 and +4.

Ag and Zn do NOT need roman numerals because Ag is always +1 and Zn is always +2.

Write the Formula

1. nickel (II) bromide NiBr2

2. lead (IV) oxide PbO2

3. iron (III) sulfide Fe2S3

Name the following

1. CrCl3 chromium (III) chloride2. FeO iron (II) oxide3. SnCl4 tin (IV) chloride4. Cu2O

copper (I) oxide

Review: Write the Formula

1. strontium fluoride

2. chromium (III) oxide

3. sulfur hexabromide

4. iron (III) sulfide5. carbon disulfide

1. SrF2

2. Cr2O3

3. SBr6

4. Fe2S3

5. CS2

Review: Name the following.

1. K2Se

2. CaI23. NiCl24. PCl35. BaNa2

1. potassium selenide

2. calcium iodide3. nickel (II)

chloride4. phosphorus

trichloride5. banana

Compounds with Polyatomic Ions

Naming Name the metal Name the polyatomic ion Use roman numeral if needed

Naming

1. MgCO3

magnesium carbonate2. Na2SO4

sodium sulfate3. Cu(OH)2

copper (II) hydroxide4. Zn(C2H3O2)2

zinc acetate

Write the Formula:

1. aluminum nitrate Al(NO3)3

2. ammonium sulfite (NH4)2SO3

3. iron (III) chlorate Fe(ClO3)3

4. calcium phosphate Ca3(PO4)2