Naming Radical Compounds

Radical compounds, also known as compound ions or polyatomic ions, are charged particles (having either positive or negative charges) made up of two or more elements in definite ratios.

Most radical compounds have a charge of -1 (often indicated only with the superscript "-"), some will hacve a charge of -2, and very few will carry a positive charge. 

The most common positively charged polyatmic ion that you will encounter is the ammonium ion  NH4+.  It has a charge of "+1".  Note that the superscript "+" in fact stands for "+1".   As all "positive" elements or in this case "cation", it will be named first in a chemical formula when it reacts with another element, ion, or compound.   

Example:

Ammonium ion + Nitrate ion --> Ammonium Nitrate

 NH4+  + NO3-  -->  NH4NO3    (The formula for ammonium nitrate is usually simplified as N2H4O3 )

List of common Radical Compounds:

Activity:

  • Familiarize yourself with the names and the respective charges of the following radical compounds. 
  • Memorize the ones highlighetd as these will be the more common ones.
     
  • acetate - C2H3O2-
  • bicarbonate - HCO3-   (also known as  hydrogen carbonate)
  • bisulfate - HSO4-or (also known as hydrogen sulfate)
  • hypochlorite - ClO-
  • chlorate - ClO3-
  • chlorite - ClO2-
  • cyanate - OCN-
  • cyanide - CN-
  • dihydrogen phosphate - H2PO4-
  • hydroxide - OH-
  • nitrate - NO3-
  • nitrite - NO2-
  • perchlorate - ClO4-
  • permanganate - MnO4-
  • thiocyanate - SCN-
  • carbonate - CO32-
  • chromate - CrO42-
  • dichromate - Cr2O72-
  • hydrogen phosphate - HPO42-
  • peroxide - O22-
  • sulfate - SO42-
  • sulfite - SO32-
  • thiosulfate - S2O32-
  • borate - BO33-
  • phosphate - PO43-