Home
Class 12
CHEMISTRY
The zinc/silver oxide cell is used in el...

The zinc/silver oxide cell is used in electric current reaction is as following:
`Zn^(2+) + 2e^(-) to Zn, E^(@) = - 0.760 V`
`Ag_(2)O + H_(2)O + 2e^(-) to 2Ag + 2OH, E^(@) = 0.344 V` If F is 96,500 C `mol^(-1)`, `DeltaG^(@)` of the cell will be:

A

`413.21 kJ mol^(-1)`

B

`113.072 kJ mol^(-1)`

C

`213.072 kJ mol^(-1)`

D

`313.082 kJ mol^(-1)`

Text Solution

AI Generated Solution

The correct Answer is:
To solve the problem, we need to calculate the standard Gibbs free energy change (ΔG°) for the zinc/silver oxide cell using the given standard reduction potentials and the Faraday constant. Here’s a step-by-step breakdown of the solution: ### Step 1: Identify the half-reactions and their standard reduction potentials The half-reactions provided are: 1. For zinc: \[ Zn^{2+} + 2e^{-} \rightarrow Zn, \quad E^{\circ} = -0.760 \, V \] 2. For silver oxide: \[ Ag_{2}O + H_{2}O + 2e^{-} \rightarrow 2Ag + 2OH^{-}, \quad E^{\circ} = 0.344 \, V \] ### Step 2: Determine the anode and cathode - The anode is where oxidation occurs. In this case, zinc is oxidized: \[ Zn \rightarrow Zn^{2+} + 2e^{-} \quad (E^{\circ} = +0.760 \, V) \] - The cathode is where reduction occurs. Silver oxide is reduced: \[ Ag_{2}O + H_{2}O + 2e^{-} \rightarrow 2Ag + 2OH^{-} \quad (E^{\circ} = 0.344 \, V) \] ### Step 3: Calculate the standard cell potential (E°cell) Using the formula: \[ E^{\circ}_{cell} = E^{\circ}_{cathode} - E^{\circ}_{anode} \] Substituting the values: \[ E^{\circ}_{cell} = 0.344 \, V - (-0.760 \, V) = 0.344 \, V + 0.760 \, V = 1.104 \, V \] ### Step 4: Calculate the number of electrons transferred (n) From the half-reactions, we see that: - 2 electrons are involved in the overall cell reaction. Thus, \( n = 2 \). ### Step 5: Use the Gibbs free energy formula The formula for Gibbs free energy change is: \[ \Delta G^{\circ} = -n E^{\circ}_{cell} F \] Where: - \( F = 96,500 \, C \, mol^{-1} \) ### Step 6: Substitute the values into the Gibbs free energy formula \[ \Delta G^{\circ} = -2 \times 1.104 \, V \times 96,500 \, C \, mol^{-1} \] ### Step 7: Calculate ΔG° Calculating: \[ \Delta G^{\circ} = -2 \times 1.104 \times 96,500 = -213,072 \, J/mol \] To convert to kilojoules: \[ \Delta G^{\circ} = -213.072 \, kJ/mol \] ### Final Answer \[ \Delta G^{\circ} = -213.072 \, kJ/mol \]

To solve the problem, we need to calculate the standard Gibbs free energy change (ΔG°) for the zinc/silver oxide cell using the given standard reduction potentials and the Faraday constant. Here’s a step-by-step breakdown of the solution: ### Step 1: Identify the half-reactions and their standard reduction potentials The half-reactions provided are: 1. For zinc: \[ Zn^{2+} + 2e^{-} \rightarrow Zn, \quad E^{\circ} = -0.760 \, V \] ...
Promotional Banner

Topper's Solved these Questions

  • ELECTROCHEMISTRY

    PHYSICS WALLAH|Exercise LEVEL-2|60 Videos
  • COORDINATION COMPOUNDS

    PHYSICS WALLAH|Exercise NEET PAST 5 YEARS QUESTIONS |8 Videos
  • ENVIRONMENTAL CHEMISTRY

    PHYSICS WALLAH|Exercise NEET Past 5 Years Questions |4 Videos

Similar Questions

Explore conceptually related problems

The zinc /silver oxide cell is used in hearing aids and electric watches . Zn to Zn^(2+) + 2 e^(-) E^(Theta) = -0.76 V Ag_(2) O + H_(2) O + 2e^(-) to 2 Ag +2 OH^(-) E^(Theta) = 0.344 V Which is oxidised and which is reduced ?

Zinc/silver oxide cell is used in hearing aids and electric watches. The following reactions occur : Zn(s) to Zn^(2+)(aq)+2e^(-) , E_(Zn^(2+)//Zn)^(@)=-0.76V Ag_(2)O+H_(2)O+2e^(-) to2Ag+2OH^(-),E_(Ag^(+)//Ag)^(@)=0.344" V" Calculate (i) Standard potential of the cell (ii) Standard Gibbs energy.

In the chemical reaction, Ag_(2)O+H_(2)O+2e^(-) to 2Ag+2OH^(-)

The half reactions for a cell are Zn to Zn^(2+) + 2e^(-), E^(@) = 0.76 V Fe to Fe^(2+) + 2e^(-), E^(@) = 0.41 V The DeltaG^(@) (in kJ) for the overall reaction Fe^(2+) + Zn to Zn^(2+) + Fe is

PHYSICS WALLAH-ELECTROCHEMISTRY-NEET PAST 5 YEARS QUESTIONS
  1. The emf of a Daniell cell at 298 K is E(1) Zn|ZnSO(4)(0.01 M)||CuSO(...

    Text Solution

    |

  2. Given that wedge(m)^(@) = 133.45 cm^(2) mol^(-1) (AgNO(3)) wedge(m)^(@...

    Text Solution

    |

  3. The zinc/silver oxide cell is used in electric current reaction is as ...

    Text Solution

    |

  4. During the electrolysis of molten sodium chloride, the time required t...

    Text Solution

    |

  5. Zine can be coated on iron to produce galvanize3d iron but the reverse...

    Text Solution

    |

  6. The number of electrons delivered at the cathode during electrolysis b...

    Text Solution

    |

  7. If the E^(@) for a given reaction has a negative value, then which of ...

    Text Solution

    |

  8. The molar conductivity of a 0.5 mol dm^(-1) solution with electrolytic...

    Text Solution

    |

  9. The pressure of H(2) required to make the potential of H(2)-electrode ...

    Text Solution

    |

  10. On elctrolysis of dil sulphuric acid using Platinum (Pt) electrode the...

    Text Solution

    |

  11. The number of Faraday.s (F) required to produce 20 g of calcium from C...

    Text Solution

    |

  12. Identify the reaction from following having top position is EMF series...

    Text Solution

    |

  13. In a typical fuel cell, the reactants (R) and product (P) are:

    Text Solution

    |

  14. For a cell involving one electron E(cell)^(0)=0.59V and 298K, the equi...

    Text Solution

    |

  15. For the cell reaction 2Fe^(2+)(aq) + 2I^(-)(aq) to 2Fe^(2+)(aq) + I(...

    Text Solution

    |

  16. Consider the change in oxidation state of Bromine corresponding to dif...

    Text Solution

    |

  17. In the electrochemical cell: Zn|ZnSO(4)(0.01 M)||CuSO(4)(1.0 M)|Cu, ...

    Text Solution

    |

  18. Given that wedge(m)^(@) = 133.45 cm^(2) mol^(-1) (AgNO(3)) wedge(m)^(@...

    Text Solution

    |

  19. The zinc/silver oxide cell is used in electric current reaction is as ...

    Text Solution

    |

  20. During the electrolysis of molten sodium chloride, the time required t...

    Text Solution

    |