Acids and bases
(i) Aqua acid: an acid in which the acid proton is on a water molecule coordinated to a central metal ion.
Example [Fe(H2O)6] 2+
(ii) Lewis acid: Is a substance that can accept pair of electrons to form a bond. Are the chemical species
which have empty orbitals and are able to accept electron pairs from Lewis bases. Examples include
copper (Cu2+), iron (Fe2+ and Fe3+), and hydrogen ion (H+ )
(iii) Bronsted acid: Is any species that is capable of donating a proton. Example HCl
(iv) Hard acid: are usually cations of electropositive metals; consequently, they are relatively nonpolarizable
and have higher charge-to-radius ratios. hard acids prefer to bind to hard bases. have small acceptor
atoms, high positive charge, and do not contain unshared pairs of electrons in their valence shell. All
these properties may not appear in one and the same acids. Therefore, these basic properties lead to
high electronegativity, low polarization, and hard to oxidize. Example H + , Li+ , Na+ , K+ , Be2+, Mg2+,
Al3+, and Ti4+ .
(v) Monoprotic acid: an acid containing one ionizable hydrogen atom per molecule. Example HCN
(vi) Polyprotic acid: An acid that contains more than one ionizable proton. The protons of these acids ionize
in steps. An acid capable of donating two or more protons.
(vii)
, OXOACIDS:
An oxoacid is an acid that contains oxygen. To be more specific, it is an acid that:
1. contains oxygen
2. contains at least one other element
3. has at least one hydrogen atom bound to oxygen
4. forms an ion by the loss of one or more protons.
Examples of oxoacids:
Carboxylic acids
Sulfuric acid
Nitric acid
Phosphoric acid
Halogen oxoacids: Hypochlorous acid; Chlorous acid; Chloric acid; Perchloric acid; Perbromic acid;
Metaperiodic acid
All oxoacids have the acidic hydrogen bound to an oxygen atom, so bond strength (length) is not a factor, as it is
with binary nonmetal hydrides. Rather, the electronegativity of the central atom (E) and the number of O atoms
determine oxoacid acidity. With the same central atom E, acid strength increases as the number of oxygen attached
to E increases. With the same number of oxygens around E, acid strength increases with the electronegativity of E.
Imidic Acids are created by replacing =O with =NR in an Oxoacid.
(i) Aqua acid: an acid in which the acid proton is on a water molecule coordinated to a central metal ion.
Example [Fe(H2O)6] 2+
(ii) Lewis acid: Is a substance that can accept pair of electrons to form a bond. Are the chemical species
which have empty orbitals and are able to accept electron pairs from Lewis bases. Examples include
copper (Cu2+), iron (Fe2+ and Fe3+), and hydrogen ion (H+ )
(iii) Bronsted acid: Is any species that is capable of donating a proton. Example HCl
(iv) Hard acid: are usually cations of electropositive metals; consequently, they are relatively nonpolarizable
and have higher charge-to-radius ratios. hard acids prefer to bind to hard bases. have small acceptor
atoms, high positive charge, and do not contain unshared pairs of electrons in their valence shell. All
these properties may not appear in one and the same acids. Therefore, these basic properties lead to
high electronegativity, low polarization, and hard to oxidize. Example H + , Li+ , Na+ , K+ , Be2+, Mg2+,
Al3+, and Ti4+ .
(v) Monoprotic acid: an acid containing one ionizable hydrogen atom per molecule. Example HCN
(vi) Polyprotic acid: An acid that contains more than one ionizable proton. The protons of these acids ionize
in steps. An acid capable of donating two or more protons.
(vii)
, OXOACIDS:
An oxoacid is an acid that contains oxygen. To be more specific, it is an acid that:
1. contains oxygen
2. contains at least one other element
3. has at least one hydrogen atom bound to oxygen
4. forms an ion by the loss of one or more protons.
Examples of oxoacids:
Carboxylic acids
Sulfuric acid
Nitric acid
Phosphoric acid
Halogen oxoacids: Hypochlorous acid; Chlorous acid; Chloric acid; Perchloric acid; Perbromic acid;
Metaperiodic acid
All oxoacids have the acidic hydrogen bound to an oxygen atom, so bond strength (length) is not a factor, as it is
with binary nonmetal hydrides. Rather, the electronegativity of the central atom (E) and the number of O atoms
determine oxoacid acidity. With the same central atom E, acid strength increases as the number of oxygen attached
to E increases. With the same number of oxygens around E, acid strength increases with the electronegativity of E.
Imidic Acids are created by replacing =O with =NR in an Oxoacid.
