Difference Between IUPAC and Common Names

Key Difference – IUPAC vs Common Names 

 

Naming chemical compounds is very important to ensure that spoken or written chemical names leave no confusion, and a single name should refer to one substance only. IUPAC names follow an internationally accepted set of rules, and all the chemical compounds get a name according to those rules. In contrast, common names can be any name that does not have common rules. Some of IUPAC names are very difficult to remember, and it is very important to memorize few basic rules in naming chemical compounds. People are more familiar with common chemical names than their IUPAC names since most of the common names are easy to remember, and they do not contain digits, prefixes, and suffixes. This is the key difference between IUPAC and Common Names.

What is IUPAC Name?

The IUPAC names are the internationally accepted method of naming chemical compounds. In general, it can be further divided into two main categories; inorganic compounds and organic compounds. No matter how many branches and how long the molecular structure is; IUPAC names can be used to name any range of molecules. But, it is really difficult to name chemical compounds accurately, without having the proper knowledge about these rules.

What is Common Name of Chemical Compounds?

The common names of chemical compounds do not follow special types of rules as in IUPAC names. In general, common names are easy to remember and convenient to use since the naming method does not consider the magnitude of the molecule, functional groups, or the molecular composition. In some occasions, some chemicals have a single name for their common name and for the IUPAC name.

What is the difference between IUPAC and Common Names?

Range:

IUPAC Names: Every chemical compound gets a name according to the IUPAC nomenclature.  The IUPAC name is directly related to its chemical structure. In other words, IUPAC names consider the functional groups, side chains, and other special bonding patterns in the molecule,

Examples:

In some molecules, IUPAC names consider the positions where functional groups are located in the molecule.

Common Names: Some chemical compounds do not have common names.Some common names are independent from their structure.

Examples:

• HCOOH – formic acid
• HCHO – formaldehyde
• C₆H₆ – Benzene
• CH₃COOH – acetic acid

Common names do not consider positions where functional groups are attached.

Examples:

Inorganic Compounds:

Formula	IUPAC Name	Common Name
NaHCO3sodium bicarbonate	sodium hydrogen carbonate	baking soda
NaBO3	sodium perborate	bleach (solid)
Na2B4O7.10 H2O	sodium tetraborate,decahydrate	Borax
MgSO4.7 H2O	magnesium sulfate heptahydrate	Epsom salt
CF2Cl2	dichlorodifluoromethane	Freon
PbS	lead (II) sulfide	galena
CaSO4.2 H2O	calcium sulfate dihydrate	gypsum
Na2S2O3	sodium thiosulfate	hypo
N2O	dinitrogen oxide	laughing gas
CaO	calcium oxide	lime
CaCO3	calcium carbonate	limestone
NaOH	sodium hydroxide	lye
Mg(OH)2	magnesium hydroxide	milk of magnesia
SiO2	silicon dioxide	quartz
NaCl	sodium chloride	salt

Organic Compounds:

Formula	IUPAC Name	Common Name
CH3-CH=CH-CH3	2-butene	Symbutane
CH3-CH(OH)-CH3	2-propanol or propan-2-ol	iso-propyl alcohol
CH3-CH2-O-CH2-CH3	Ethoxy ethane	Diethyl ether
HCOOH	Methanoic acid	Formic acid
CH3COOH	Ethanoic acid	Acetic Acid
CH3-CO-OCH2-CH3	Ethyl ethanoate	Ethyl acetate
H-CO-NH2	Methanamide	Formamide

 

Image Courtesy:

1. Calcium Carbonate By Edgar181 (Own work) [Public domain], via Wikimedia Commons

2. A seashell is largely made of Calcium Carbonate By Hi-Res Images of Chemical Elements [CC BY 3.0], via Wikimedia Commons