Richard Lizius
01/10/2004
Acids
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Are substances which yield the hydrogen ion, H+1, when in solution.
ACIDS are the opposite of BASES or HYDROXIDES
Acids are of two types: Binary acids and Oxyacids
Binary Acids
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As the name implies, these compounds consist of only two elements, one of which
is hydrogen and the other in a non-metal
There are only five of these compounds
When the covalent compounds are dissolved in water they form acids. (hydrogen
must form a polar covalent bond with a non-metal, therefore only some elements
have the right electronegativity values F, Cl, Br, I, S)
Naming:
Classical
• These acids all begin with the prefix “hydro” followed by the name of the
non-metal ending in the suffix “ic”.
IUPAC
• The word “aqueous” precedes the name of the dissolved compound.
Formula
Classical Name
IUPAC Name
HF(aq)
HCl(aq)
HBr(aq)
HI(aq)
H2S(aq)
hydrofluoric acid
hydrochloric acid
hydrobromic acid
hydroiodic acid
hydrosulfuric acid
aqueous hydrogen fluoride
aqueous hydrogen chloride
aqueous hydrogen bromide
aqueous hydrogen iodide
aqueous hydrogen sulfide
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The chemical formulas always have the subscript (aq) indicating that they are
dissolved in water.
HCl(g) means hydrogen chloride
HCl(aq) means hydrochloric acid or aqueous hydrogen chloride
In addition, although not a binary acid, it uses the same system:
Hydrogen cyanide
HCN
Hydrocyanic acid
Oxyacids
These are the hydrogen compounds of the oxyanions.
• The classical name of the main acids all end in “ic”
• The IUPAC names include the prefix “aqueous” followed by the name of the
dissolved compound
Richard Lizius
01/10/2004
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The seven main oxyacids are:
Formula
Classical Name
IUPAC Name
HNO3 (aq)
HClo3 (aq)
HBrO3 (aq)
HIO3 (aq)
H2CO3 (aq)
H2SO4 (aq)
H3PO4 (aq)
nitric acid
chloric acid
bromic acid
iodic acid
carbonic acid
sufluric acid
phosphoric acid
aqueous hydrogen nitrate
aqueous hydrogen chlorate
aqueous hydrogen bromate
aqueous hydrogen iodate
aqueous hydrogen carbonate
aqueous hydrogen sulfate
aqueous hydrogen phosphate
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As with oxyanions, oxyacids also have derivatives based on the number of
oxygens in the compound
The IUPAC names include the prefix “aqueous” followed by the name of the
dissolved compound
The classical names include a prefix and suffix to indicate the number of oxygen
atoms contained in the acid relative to the main or “IC” acid.
One oxygen added
MAIN ACID
One oxygen removed
Tow oxygen removed
per…….ic acid
……ic acid
..….ous acid
hypo…..ous acid
“ate” oxyanion”
“ite” oxyanion
Formula
Classical Name
IUPAC Name
H3PO5 (aq)
perphosphoric acid
aqueous hydrogen perphosphate
Acid Salts
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Oxyacids may lose all of their hydrogens to become oxyanions
For oxyacids that contain more than 1 hydrogen, they can lose their hydrogens
one at a time and form acid salts with metal ions.
These oxyacids are called “diprotic” (2 hydrogens) or “triprotic” (3 hydrogens)
Diprotic acids are H2SO4 and H2CO3 and ALL their derivatives.
• If they lose a single hydrogen atom they form these polyatomic ions.
HSO41HCO31•
called hydrogen sulphate or bisulphate
called hydrogen carbonate or bicarbonate
Amphoteric (can either gain or lose and electron in water to become basic or acid)
Triprotic Phosphoric acid, can form two different polyatomic ions:
• Loss of 2 hydrogens
Richard Lizius
01/10/2004
HPO42•
called hydrogen phosphate or biphosphate
Loss of one hydrogen
H2PO41-
called dihydrogen phosphate (exception to the rule that you don’t give
hydrogen compounds a prefix because there is already a hydrogen
phosphate).
Salts containing acid anions:
NaHCO3
is sodium hydrogen carbonate or sodium bicarbonate (produces water,
carbon dioxide and sodium oxide)
Bases
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Are substances which yield the hydroxide ion, OH-1, when in solution.
BASES are the opposite of ACIDS.
These are aqueous solutions of metal hydroxides
Name
• Is the name of the ionic hydroxide, preceded by “aqueous”
Formula
• Is the formula of the metal hydroxide with an (aq) subscript
NaOH(aq)
aqueous sodium hydroxide