Wednesday 2 November 2011

Naming Compounds Part 2!

Today Mr Doktor explained to us how to name molecular compounds, acids and bases. There are various rules for naming these compounds:

Molecular Compounds:
- There are 7 Diatomic molecules: H2, N2, O2, F2, Cl2, Br2, I2
- There are 2 Polyatomic molecules: S8, P4

Rules for naming a molecular compound:
- Use the name of the first element
- Second element ends in -ide
- 1st atom usually does not have a prefix (Ex. NO -> Nitrogen monoxide)
- Hydrogen doesn't have a prefix (Ex. H2S -> Hydrogen sulfide)
- Some compounds are to be memorized:

IUPAC Name Formula
Water H20
Hydrogen Peroxide H2O2
Ammonia NH3
Glucose C6H12O6
Sucrose C12H22O11
Methane CH4
Propane C3H8
Octane C8H18
Mathanol CH3OH
Ethanol C2H5OH

Naming Acids:
- Hydrogen compounds are acids (Ex. HCl -> Hydrochloric acid, H2SO4 -> Sulphuric acid)
- Hydrogen appears first in the formula unless it is part of a polyatomic group (Ex. CH3OOOH -> Acetic Acid)
- Classical rules use the suffix -ic and/or the prefix hydro- (Ex. Sulphuric acid, Hydrochloric acid)
- IUPAC system uses the aqueus hydrogen compound (Ex. HCl (aq) -> Aqueous Hydrogen Chloride)

Naming Bases:
- Cation and OH (Ex. NaOH, Ba(OH)2)
- Use the cation name followed by "hydroxide" (Ex. Sodium Hydroxide, Barium Hydroxide)

Some Acids and Bases:
Acid/Base Compound
Hydrochloric Acid HCl
Nitric Acid HNO3
Suphuric Acid H2SO4
Phosphoric Acid H3PO4
Acetic Acid CH3COOH
Ammonia NH3

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