Tables of Common Polyatomic Ions


List of Tables:


The tables below list common polyatomic ions that you will be using throughout this General-Chemistry laboratory series (Chem 151-152). These ions are separated by charge on the ion into four (4) different tables and listed alphabetically within each table. For each polyatomic ion, the name, chemical formula, two-dimensional drawing, and three-dimensional representation are given.

The three-dimensional structures are drawn as CPK models. CPK structures represent the atoms as spheres, where the radius of the sphere is equal to the van der Waals radius of the atom; these structures give an approximate volume of the polyatomic ion. In these tables, the three-dimensional structures have all been drawn to the same scale; therefore you can compare their relative sizes. In addition, the atoms in the CPK structures have been color-coded to match the two-dimensional drawings for easier comparison.

To view the ions interactively, please use RASMOL, a computer application which is available for both Macs and PCs and can be downloaded at the RASMOL site. To download the pdb files (refers to the protein databank method of saving atomic coordinates for a molecule) for viewing and rotating the ions listed in the tables below, please click on the appropriate three-dimensional structure. (Note: If you want to view multiple compounds simultaneously, please download each pdb file and save on your computer. Then open RASMOL outside of Netscape.) NOTE: CPK sizes for metal atoms Cr and Mn will be incorrect in RASMOL.


Table 1: Cations (+1 Charge)

Ion

Two-Dimensional Structure

Three-Dimensional Representation

Ammonium NH4+

Hydronium H3O+

Index

Table 2: Anions (-1 Charge)

Ion

Two-Dimensional Structure

Three-Dimensional Representation

Bicarbonate HCO3-

Cyanide CN-

Hydrogen Sulfate HSO4-

Hydroxide OH-

Nitrate NO3-

Nitrite NO2-

Perchlorate ClO4-

Permanganate MnO4-

Index

Table 3: Anions (-2 Charge)

Ion

Two-Dimensional Structure

Three-Dimensional Representation

Carbonate CO32-

Chromate CrO42-

Dichromate Cr2O72-

Hydrogen Phosphate HPO42-

Sulfate SO42-

Sulfite SO32-

Thiosulfate S2O32-

Index

Table 4: Anions (-3 Charge)

Ion

Two-Dimensional Structure

Three-Dimensional Representation

Phosphate PO43-

Index



Selected by the sciLINKS program, a service of the National Science Teachers Association. Copyright 2001.
Copyright 1998, Washington University, All Rights Reserved.