Common Molecular Names, Acids, and Polyatomic Ions Study Guide

General Information and Academic Preparation

  • The material includes a designation for LORGAR and amScanner.

  • Note: There is a test scheduled on page 4.

Common Names of Molecular Substances

Some molecular substances are so common that a common name is generally used for them instead of following standard naming rules. It is essential to learn these formulae and common names well.

  • Ammonia: NH3NH_3

  • Hydrogen sulfide: H2SH_2S

  • Water: H2OH_2O

  • Hydrogen peroxide: H2O2H_2O_2

  • Hydrogen chloride: HC (g)HC\,(g)

  • Hydrogen bromide: HBrHBr

  • Hydrogen iodide: HIHI

  • Hydrogen fluoride: HFHF

Chemical Formulae and Common Names for Acids

The following acids and their associated common names must be memorized:

  • Hydrochloric acid: HCHC

  • Sulfuric acid: H2SO4H_2SO_4

  • Nitric acid: HNO3HNO_3

  • Carbonic acid: H2CO3H_2CO_3

  • Acetic/ethanoic acid: CH3COOHCH_3COOH

Common Polyatomic Ions

The following table of polyatomic ions must be learned very well. Knowledge of their specific formula, name, and charge is required.

1+ Ions

  • Ammonium ion: NH4NH_4

1- Ions

  • Hydroxide ion: OH−OH^-

  • Nitrate ion: NO3NO_3

  • Hydrogen carbonate ion or bicarbonate ion: HCO3HCO_3

  • Acetate ion or ethanoate: CH3COOCH_3COO

2- Ions

  • Carbonate ion: CO2−CO2^-

  • Sulfate ion: SO42−SO42^-

  • Sulfite ion: SO32−SO32^-

3- Ions

  • Phosphate ion: PO43−PO43^-