Write two half-reactions to describe each of these metal displacement reactions. Include phase symbols.

Question

Write two half-reactions to describe each of these metal displacement reactions. Include phase symbols.

Cu(s)+2 AuCl(aq)--->CuCl₂ (aq)+2 Au(s)

oxidation half-reaction?

reduction half-reaction:?

Answer 1

Cu(s) + 2AuCl(aq) ==> CuCl2(aq) + 2Au(s)

Cu(s) goes from oxidation number 0 to oxidation number 2⁺ in CuCl2. It has been oxidized.

Au in AuCl goes from oxidation number 1+ to zero in Au(s). It has been reduced.

Oxidation half reaction: Cu(s) ===> Cu²⁺(aq) + 2e-

Reduction half reaction: Au⁺(aq) + e- ===> Au(s)

(NOTE: the reduction half reaction is NOT balanced. Multiply by 2 to equalize the electrons)

BALANCED REACTIONS:

Oxidation half reaction: Cu(s) ===> Cu²⁺(aq) + 2e-

Reduction half reaction: 2Au⁺(aq) + 2e- ===> 2Au(s)

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OVERALL RXN: Cu(s) + 2Au⁺(aq) ===> Cu²⁺(aq) + 2Au(s)