Nomenclature Part IISalts Containing Polyatomic Ions

AcidsOxyacids

HW: Read 4-4 &4-6 Do problems 32, 34, 47, & 48 on pgs 133-134

Naming Compounds Containing Polyatomic

Ions

Polyatomic Ions Polyatomic Ions are groups of more than

one atom that are bonded covalently, and have a net charge.

There are several polyatomic ions that whose names and formulas MUST be memorized.

They are found on table 4-2 on page 122. This website may also be helpful…

http://antoine.frostburg.edu/chem/senese/101/compounds/polyatomic.shtml

How to name polyatomic ions in compounds.

Polyatomic ions are found in nonbinary ionic compounds, and in oxyacids.

To name a polyatomic Ion in an ionic compound:

• If the poly atomic ion is first, and the anion is monoatomic, name the polyatomic ion, then name the anion as usual, replacing its ending with the suffix –ide.

• If the polyatomic ion is second, first name the cation as a type I or type II depending on what it is, including the roman numerals for type II, then name the polyatomic ion.

• If both cation and anion are polyatomic, just name each polyatomic ion in the order in which they occur.

Practice: Name the following Compounds that contain Polyatomic Ions.

Na2SO4

Fe(NO3)3

Na2SO3

KH2PO4

Mn(OH)2

NH4ClO3

Sodium sulfate

Iron (III) Nitrate

Sodium Sulfite

Potassium Dihydrogen

Phosphate

Manganese (II)

Hydroxide

Ammonium Chlorate

Practice: Name the following Compounds that contain Polyatomic Ions.

Ca(OH)2

Na3PO4

KMnO4

(NH4)2Cr2O7

Co(ClO4)2

KClO3

Cu(NO2)2

Calcium Hydroxide

Sodium Phosphate

Potassium

Permanganate

Ammonium Dichromate

Cobalt (II) Perchlorate

Potassium Chlorate

Copper (II) Nitrate

Naming Acids

What are Acids? There are several definitions of acids.

For now, an acid is a compound whose formula starts with hydrogen.

There are two types of acids:1. Regular Acids2. Oxyacids

Regular Acids Regular Acids are binary compounds

containing hydrogen and one other nonmetal.

The hydrogen will always come first.• Examples: HCl, H2S, H3N

How do you tell how many H’s the acid of a nonmetal will have?• Balance the known charge of the nonmetal

by adding Hydrogen (each H = 1+ charge).

Naming Regular Acids Naming Regular Acids

1. Use the prefix Hydro- 2. Use the nonmetal’s root 3. Use the suffix –ic 4. Finish with the word acid.

Hydro-”root”-ic Acid• HCl = Hydrochloric Acid• H2S = Hydrosulfuric Acid

• H3N = Hydronitric Acid

Practice: Name the following Regular Acids

HF

HI

HBr

H2O

H2Se

H3As

H3P

Hydrofluoric Acid

Hydroiodic Acid

Hydrobromic Acid

Hydroxic Acid

Hydroselenic Acid

Hydroarsenic Acid

Hydrophosphoric Acid

Oxyacids Oxyacids contain hydrogen, oxygen,

plus one other nonmetal.. The hydrogen comes first. The oxygen and other element make

up a polyatomic anion called an oxyanion.• Example: ClO4

-, CO32-, NO3

-, NO2-, etc…

Remember you add the number of hydrogen atoms needed to balance the charge on the oxyanion.

Naming Oxyacids Oxyacids are named using the oxyanions

from which they are made. If the oxyanion ends in –ate, then the suffix

is changed to –ic, followed by the word acid.• HNO3 contains nitrate (NO3

-): it is called nitric acid If the oxyanion ends in –ite, then the suffix is

changed to –ous, followed by the word acid.• HNO2 contains nitrite (NO2

-): it is called nitrous acid

Practice: Name the following Oxyacids

H2SO4

H2SO3

H3PO4

H2CO3

HClO

HC2H3O2

HCN

Sulfuric Acid

Sulfurous Acid

Phorphoric Acid

Carbonic Acid

Hypochlorous Acid

Acetic Acid

Hydrocyanic Acid