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Determine the cell reaction and standard cell potential at 25 °C for a cell made from a cathode half-cell consisting of a silver electrode in 1 M silver nitrate solution and an anode half-cell consisting of a zinc electrode in 1 M zinc nitrate. Is the reaction spontaneous at standard conditions?

a) Cell Reaction: Zn(s) + 2Ag⁺(aq) → Zn²⁺(aq) + 2Ag(s), Standard Cell Potential: 1.56 V, Spontaneous: Yes
b) Cell Reaction: (Zn²⁺(aq) + 2Ag(s) → Zn(s) + 2Ag⁺(aq), Standard Cell Potential: -1.56 V, Spontaneous: No
c) Cell Reaction: Zn(s) + 2Ag⁺(aq) rightarrow Zn²⁺(aq) + Ag(s), Standard Cell Potential: 0.56 V, Spontaneous: Yes
d) Cell Reaction: Ag(s) + Zn²⁺(aq) rightarrow Ag⁺(aq) + Zn(s), Standard Cell Potential: -0.56 V, Spontaneous: No

User Kamal
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1 Answer

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Final answer:

The cell reaction for a cell composed of zinc and silver nitrate half-cells is Zn(s) + 2Ag⁺(aq) → Zn²⁺(aq) + 2Ag(s), with a standard cell potential of 1.56 V, indicating that the reaction is spontaneous under standard conditions.

Step-by-step explanation:

To determine the cell reaction and standard cell potential for the galvanic cell in question, we refer to the standard reduction potentials of zinc and silver. The anode half-cell reaction, where oxidation takes place, involves zinc (Zn) turning into zinc ions (Zn²⁺). The corresponding reduction (opposite of oxidation) half-cell potential is -0.76 V. For the cathode, where reduction takes place, silver ions (Ag⁺) are reduced to silver (Ag). The standard reduction potential for silver is +0.80 V. In a galvanic cell, the anode half-cell potential is reversed (oxidation) when calculating the total cell potential.

The overall cell reaction is:

Zn(s) + 2Ag⁺(aq) → Zn²⁺(aq) + 2Ag(s)

To find the standard cell potential (E°ₒₓₑₙ), we add the standard potential of the cathode to the inverse of the standard potential of the anode:

E°ₒₓₑₙ = E°ₒₓₑₙ(cathode) - E°ₒₓₑₙ(anode)
E°ₒₓₑₙ = (+0.80 V) - (-(0.76 V))
E°ₒₓₑₙ = +1.56 V

The reaction is spontaneous at standard conditions because the standard cell potential is positive. Therefore, the correct option is:

a) Cell Reaction: Zn(s) + 2Ag⁺(aq) → Zn²⁺(aq) + 2Ag(s), Standard Cell Potential: 1.56 V, Spontaneous: Yes

User Anirudha
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