Complete and balance the following redox reaction in basic solution. Be sure to include the proper phases for all species within the reaction. Te(s) + NO3(aq)- --> TeO3^2- (aq) + N2O4(g)

Answer 1

Use the half-reaction method.

Oxidation:

Te(s) ==> TeO₃^2-(aq) ... unbalanced oxidation half reaction

Te(s) + 3H₂O(l) ==> TeO₃^2-(aq) ... balanced for Te and O

Te(s) + 3H₂O(l) + 6OH^-(aq) ==> TeO₃^2-(aq) + 6H₂O(l) ... balanced for Te, O and H using base (OH^-)

Te(s) + 3H₂O(l) + 6OH^-(aq) ==> TeO₃^2-(aq) + 6H₂O(l) +4e- ... final balanced oxidation reaction

Reduction:

NO₃^-(aq) ==> N₂O₄(g) ... unbalanced reduction half reaction

2NO₃^-(aq) ==> N₂O₄(g) ... balanced for N

2NO₃^-(aq) ==> N₂O₄(g) + 2H₂O(l) ... balanced for N and O

2NO₃^-(aq) + 4H₂O(l) ==> N₂O₄(g) + 2H₂O(l) + 4OH^-(aq) ... balanced for N,O and H using base (OH-)

2NO₃^-(aq) + 4H₂O(l) +2e- ==> N₂O₄(g) + 2H₂O(l) + 4OH^-(aq) ... final balanced reduction reaction

To equalized electrons transferred, multiply reduction reaction by 2 and add to oxidation reaction:

Te(s) + 3H₂O(l) + 6OH^-(aq) ==> TeO₃^2-(aq) + 6H₂O(l) +4e-

4NO₃^-(aq) + 8H₂O(l) +4e- ==> 2N₂O₄(g) + 4H₂O(l) + 8OH^-(aq)

Add together and combine/cancel like tems:

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Te(s) + H₂O + 4NO₃^-(aq) + ==> TeO₃^2-(aq) + 2N₂O₄(g) + 2OH^-(aq) ... balanced redox