March 05, 2013
Oxidizing and Reducing
Agents
Oxidizing Agents
-are reduced (gain e-)
Examples
metal ions (M+)
non metals
acids
Not all OA's have the same
strength. Some are better
at gaining electrons. This
makes them more reactive.
(stronger)
Reducing Agents
-are oxidized (lose e-)
Examples
metals
anions (N-)
Not all RA's have the same
strength. Some are better
at losing electrons. This
makes them more reactive.
(stronger)
March 05, 2013
Oxidizing Agents
-are reduced (gain e-)
Reducing Agents
-are oxidized (lose e-)
Examples
metals
anions (N-)
Not all RA's have the same
strength. Some are better
at losing electrons. This
makes them more reactive.
(stronger)
Examples
metal ions (M+)
non metals
acids
Not all OA's have the same
strength. Some are better
at gaining electrons. This
makes them more reactive.
(stronger)
When an OA is reduced, it becomes an RA
Cu2+(aq) + 2e- ----> Cu(s)
OA + e- ----> RA
March 05, 2013
Example
SO42-(aq) + 4 H+(aq) + 2e- ---> H2SO3(aq)
Is H2SO3(aq) an oxidizing agent or a reducing agent?
When a RA is oxidized it becomes an OA
Pb(s) ---> Pb2+(aq) + 2e-
RA ---> OA + e-
March 05, 2013
Rule for Comparing OA and RA strength
If a substance is a strong OA, it is a weak RA in its
reduced form. (and vice versa)
OA + e- ---> RA
Example
Reactive metals like sodium are strong reducing agents.
Are Na+(aq) a weak or strong oxidizing agent?
March 05, 2013
Redox Tables
A redox table is a series of reduction reactions listed with
the strongest OA at the top left
The strongest RA is on the bottom right
The reactions are reversible (can be read forward and
backwards
March 05, 2013
Your redox table is on page 7 of the data book
March 05, 2013
Which is a stronger OA
Br2(l) or Fe3+(aq)
SO42-(aq) and H+(aq)
or Ag+(aq)
March 05, 2013
Fe2+ can gain electrons or lose electrons (this is common in
multivalent metals)
Write the half reaction when Fe2+ is reduced.
Water can act as an OA or an RA.
Write the reaction when water acts as an RA.
Is water a weak or strong RA?
March 05, 2013
A redox table can be used to determine if an OA
and RA will react spontaneously with each other.
Rule for Predicting Sponteneity
An OA and RA will react spontaneously with each other
if the OA is above the RA on the redox table
Identify three metals that react spontaneously with nitric acid.
March 05, 2013
A salt solution contains Na+(aq) and Cl-(aq). Do these ions react
spontaneously with each other?
Will H2(g) react spontaneously with copper (II) ions
Will H2(g) react spontaneously with lead(II) ions
March 05, 2013
bottom half
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March 05, 2013
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