Oxidation Numbers
What is the oxidation number of any element in its standard state, such as O2 (g) or Fe (s)?
0
Oxidizing agent/ being reduced
Write the oxidation half reaction for: Mg + Cl2 -> MgCl2
Mg -> Mg2+ + 2e-
Determine the oxidation state of sulfur in the sulfate ion
+6
In the reaction Zn (s) + Cu2+ (aq) -> Zn2+ (aq) + Cu(s), which element is being oxidized
Zn
In a balanced reduction half reaction, on which side of the arrow do the electrons appear?
Reactants (e- are gained)
In the compound K2Cr2O7 what is the oxidation number for chromium?
+6
Define what happens to the reducing agent during a chemical reaction
the reducing agent is oxidized (loses e-)
Write the balanced reduction half reaction for the conversion Fe3+ to Fe2+
Fe3+ + e- -> Fe2+
Identify the oxidation state of H in NaH.
-1
Identify the oxidizing agent in the following reaction: CH4 + 2O2 -> CO2 + 2H2O
O2
Split the following reaction into its two half reactions: 2Al + 3Sn2+ -> 2Al3+ + 3Sn
O: 2Al -> 2Al3+ + 6e-
R: 3Sn2+ + 6e- -> 3Sn
Assign the oxidation numbers to all the atoms in the nitrate ion
+5 N
-2 O
Is the following a redox reaction? If so identify the specied being reduced:
AgNO3 (aq) + NaCl (aq) -> AgCl + NaNO3
No. this is a precipitation (double displacement). All oxidation numbers stayed the same
Find the half reactions of the following: Mg + N2 -> Mg3N2
O: Mg -> Mg2+ + 2e-
R: N2 + 6e- -> 2N3-