When a magnesium wire is dipped into a solution of lead (II) nitrate, a black deposit forms on the wire. Which of the following
can be concluded from this observation?
(A) The standard reduction potential, Eo , for Pb2+(aq) is greater than that for Mg2+(aq).
(B) Mg(s) is less easily oxidized than Pb(s).
(C) An external source of potential must have been supplied.
(D) The magnesium wire will be the cathode of a Mg/Pb cell.
(E) Pb(s) can spontaneously displace Mg2+(aq) from solution.
...
(A) The standard reduction potential, Eo , for Pb2+(aq) is greater than that for Mg2+(aq).
(B) Mg(s) is less easily oxidized than Pb(s).
(C) An external source of potential must have been supplied.
(D) The magnesium wire will be the cathode of a Mg/Pb cell.
(E) Pb(s) can spontaneously displace Mg2+(aq) from solution.
...
1 answer:
Answer:The standard reduction potential, Eo , for Pb2+(aq) is greater than that for Mg2+(aq).
Explanation:
Metals are usually arranged in an order of reactivity called activity series. Metals that are high up in the series are good reducing agents with very low (very negative) reduction potentials. Metals with greater (less negative) reduction potentials are found lower in the series. In the image attached, elements were arranged according to their reducing ability. Magnesium is very electro positive hence it is a better reducing agent with a lesser standard reduction potential than lead(refer to the image for numerical values of standard reduction potentials). Hence it displaces lead from solution and the elemental lead deposits on the wire.
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Answer:
Based on compounds given, NO reaction occurs
Explanation
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The Molecular Equation is ...
NH₄Cl(aq) + AgNO₃(aq) => NH₄NO₃(aq) + AgCl(s)
Silver chloride forms in this reaction as a solid precipitate because of its low solubility and is the 'Driving Force' of the reaction. Driving Force is a more stable compound than any on the reactant side and when formed leaves the reaction system as a solid ppt, liquid weak electrolyte (i.e., weak acid or weak base) or a gas decomposition product of a weak electrolyte.
The Ionic Equation is ...
NH₄⁺(aq) + Cl⁻(aq) + Ag⁺(aq) + NO₃⁻(aq) => NH₄⁺(aq) + NO₃⁻(aq) + AgCl(s)
This shows all ions from reaction plus the Driving Force of the reaction.
The Net Ionic Equation is ...
Ag⁺(aq) + Cl⁻(aq) => AgCl(s)
The Net Ionic Equation shows only those ions undergoing reaction. The NH₄⁺ and NO₃⁻ ions are 'Spectator Ions' and do not react.
Attached is a reference sheet for determining the Driving Force of a Metathesis Double Replacement Reaction. Suggest reviewing acid-base theories and the products of decomposition type reactions.
