Memorizing the ions is one of the most challenging part of mastering the basics of inorganic nomenclature.  As I agree with Gerhand, Lind (1992), students of chemistry should master the naming and writing inorganic compounds. With this, I am suggesting the following aids that students and teachers of general chemistry may find helpful.

 I believe, however, that memorizing the ions  should be a behavioral learning process because to be fluent in the language, one should automatically remember the ions.  This can be likened to typewriting or keyboarding where the fingers move fast automatically in response to the words that are heard or seen (stimulus).  On the other hand, cognitive learning, is not automatic,  an information (stimulus) has to be processed first in the brain (thinking, associating and deciding) before the desired information is remembered.  Nevertheless, with respect, I am leaving the final choice to the learners and the teachers, thus the following options as aids in memorizing the ions. A Combination may work best.

It should be noted that the IUPAC is the authorized organization to set the rules of inorganic nomenclature. Thus, the suggestions here are not intended to overlap with the recommended rules of the IUPAC. The following suggestions are an outgrowth of a combination of IUPAC recommended rules, the creative craft on these rules in the article of Richard Lind (1992) and the experience of the author.

 OPTION 1: Behavioral Process

Remember that repetition enhances memory retention.

  1. Get a blank bond paper and fold it in two equal parts (lengthwise).
  2. On one side of the paper, write the names of the cations and on the other side, their symbols.
  3. Memorize the symbols and the names of the ions.
  4. Rehearse your memory by looking at the names of the ions you have written on one side of the folded paper. Then get another paper and write, out of your memory, the symbols of the ions matching their names.
  5. Repeat No. 4, but this time by looking at the symbols then write the names.
  6. Repeat No. 4 and 5 until you have mastered the names and symbols of the ions.
  7. Repeat Steps 1 to 7 for anions. 

OPTION 2: Cognitive Process 

Aid  1.  KNOW THIS!!!

Knowing the following information can help you recall the ions.

For cations,  ( Prepare your periodic table)

A. Cations with fixed charge

B.  Cations with variable charge

1.  All Group 1A metals, the Alkali metal ions take a +1 charge.

 

2.  All Group IIA metals, the Alkaline Earth metal ions take a +2 charge.

 

Use numerals (Roman or Arabic) to distinguish them

Example:   Iron has variable charge of 2+ and 3+ , thus to specify one from the other numerals (to represent a number of charges) are used to name them.

      Fe2+  is written as Iron(II) or Iron(2+)  

     Fe3+  is written as Iron(III) or Iron(3+)

For anions

A. For anions with -1 charge

B.  For Polyatomic ions

1. They take the suffix  “-ide” in their name

            - most monatomic anions follow  this (Exceptions; hydroxide and cyanide)such as sulfide and nitride

 2.  Halogens, as halide ions  take a fixed     “1- charge” such as fluoride and chloride

 

1. They take either the suffix “ite” or “ate” such as sulfite and sulfate.

 

 

 


For Oxyanions

 

Naming OXYANIONS (Lind, R, 1992)

( anions with variable number of oxygen atoms)

With 2 Variable number of Oxygen atoms (less and more)

 

1.  less number of oxygen atom takes the suffix   ____ite.

2.  more number of oxygen atom takes the suffix _____ate

Ex.  

       NO21-   nitrite

       NO31-   nitrate

Test yourself:  What are the names of SO32-  and SO42-?

 

 

With 3 to 4 variable number of oxygen atoms (least, less, more most)

 

1.  Least number of O atoms takes the prefix and suffix  “hypo___ite”

2.  Less (2nd from the least) number of O atoms takes the suffix  “____ite”

3.  More (3rd from the least) number of O atoms takes the prefix “____ate”

4. Most number of O atoms takes the suffix and prefix  “ per____ate”

Ex.

   ClO1-   least O   hypochlorite

   ClO21-  less  O   chlorite

   ClO31-  more O  chlorate

   ClO41-  most  O  perchlorate

Test yourself: What are the names of  BrO1-, BrO21, BrO21-, and BrO41-?

 

 For oxyanions  with hydrogen

Naming oxyanions with hydrogen atom

1. One hydrogen atom in the oxyanion either name the hydrogen or use the prefix “bi”

Ex.   HSO31-     hydrogen sulfite    or bisulfite

2.  Two or more hydrogen atoms in the oxyanion use the Greek prefix +  “hydrogen”

Ex.  H2BO4     dihydrogenborate ( here, there are 2 H   thus, dihydrogen)

Test yourself:

What is the name of the oxyanion  H2PO41- ?

Aid 2: SIMPLY ASSOCIATE THIS ( The use of mnemonics)

The suggested mnemonics below are intended to help you memorize the ions as categorized according to charge for cations, and according to charge and suffixes for anions.

It is for you to decide whether these mnemonics suit you. If not, you may create your own. However, if you intend to use these mnemonics you may follow the procedure below.

  1. memorize the names of the cations and anions using the mnemonics below.

  2. Then test yourself by following the steps Option 1 above.

MNEMONICS FOR CATIONS

I. With Fixed 1+ Charge

Suggested mnemonics: “F1 HyPoCriSy ”

Where, F1 means Francium and the others have 1+ charge, Hy for hydrogen, Po for potassium, CriSy for Cesium and Silver

II. With Fixed 2+ Charge

Suggested mnemonics: “Can a zing, strong, brave bare cat call 2 times?”

Where;

Can for cadmium, zing for zinc, strong for strontium, brave for barium, bare for beryllium and radium, call for calcium, 2 times for 2+ charge

III. With Variable Charge

  1. For cation ion with 2+/3+ charge.

Suggested mnemonics: “Iron Man Called “Nick Chrom 23 times”

Where: 23 times stands for 2+ and 3+ cations; Iron for Iron(II) and Iron (III); Man for Manganese(II) and Manganese(III); Called for Cobalt(II) and Cobalt(III); Nick for Nickel(II) and Nickel(III); and Chrom for Chromium(II) and Chromium(III)

  1. For cations with 2+/4+ charge.

Suggested mnemonics: “Tim leads by 24 points”

Where: 24 points stands for 2+ and 4+ cations; Leader for Lead(II) and Lead(IV);

Tim for Tin(II) and Tin(IV)

C.For cations with 1+/2+ charge

Suggested mnemonics: “A dozen for Merco”

Where: A dozen stands for 1+ and 2+ cations; Mer for Mercury(I) and Mercury(II); Co for Copper(I) and Copper(II)

D. For cations with 2+/5+ charge and 1+/3+ charge

Suggested mnemonics: “Aunt was busy for 25yrs in carrying 13 gold rings.”

Where: 25yrs stands for 2+ and 5+; Aunt for Atimony(II) and Antimony(V); Busy

for Bismuth(II) and Bismuth(V); 13 for 1+ and 3+; gold rings for Gold(I) and

Gold(III)

References

Lind, R. (1992).  “Teaching Inorganic Nomenclature A Systematic Approach”. Journal of Chemical Education 69(8) 613-614.  Retrieved January 16, 2015 from   http://pubs.acs.org/doi/abs/10.1021/ed069p613

Nomenclature of Inorganic Chemistry IUPAC Recommendations 2005.Cambridge, UK: RSC Publishing.

Tabinas, C (2006).  Naming and Writing Simple Inorganic ChemicalFormulas Module and Text with Worksheets. Philippines: C&E Publishing, Inc. pp. 2-3; 91-92.