#cell potential

Variation of Conductivity with Concentration and Measurement

A cell operates with Ecell = 1.50 V at 298 K when [Anode] = 0.001 M and [Cathode] = 0.1 M . If E°cell = 1.44 V , what is

Ecell = E°cell - (0.059/n) log Q , 1.50 = 1.44 - (0.059/2) log Q . 0.06 = -0.0295 log Q , log Q = -(0.06/0.0295) = -2.034, Q = 10⁻².⁰³⁴ ≈ 0.0092 . Since Q = ([Anode]/[Cathode]) = (0.001/0.1) = 0.01 , matches approximately.

Ref: NCERT Class 12 Chemistry > Chapter 2: Electrochemistry > Topic: Variation of Conductivity with Concentration and Measurement

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Variation of Conductivity with Concentration and Measurement

What is the equilibrium constant for a cell reaction with E°cell = 0.236 V at 298 K involving 2 electrons?

E°cell = (0.059/n) log Kc . 0.236 = (0.059/2) log Kc , log Kc = 8, Kc = 10⁸ .

Ref: NCERT Class 12 Chemistry > Chapter 2: Electrochemistry > Topic: Variation of Conductivity with Concentration and Measurement

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Variation of Conductivity with Concentration and Measurement

A cell reaction has E°cell = 0.74 V and Δr G° = -142610 J/mol at 298 K. How many electrons are transferred? (F = 96500 C

Δr G° = -n F E°cell , -142610 = -n × 96500 × 0.74 . n = (142610/96500 × 0.74) = (142610/71410) ≈ 2 .

Ref: NCERT Class 12 Chemistry > Chapter 2: Electrochemistry > Topic: Variation of Conductivity with Concentration and Measurement

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Variation of Conductivity with Concentration and Measurement

A cell has E°cell = 0.59 V and an equilibrium constant of 10²⁰ at 298 K. How many electrons are transferred?

E°cell = (0.059/n) log Kc , 0.59 = (0.059/n) × 20 , n = (1.18/0.59) = 2 .

Ref: NCERT Class 12 Chemistry > Chapter 2: Electrochemistry > Topic: Variation of Conductivity with Concentration and Measurement

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Variation of Conductivity with Concentration and Measurement

What is the standard emf of a cell with the reaction Co(s) + Ni²⁺(aq) → Co²⁺(aq) + Ni(s) ? (Given: E°Co²⁺/Co = -0.28 V ,

E°cell = E°cathode - E°anode = -0.25 - (-0.28) = 0.03 V .

Ref: NCERT Class 12 Chemistry > Chapter 2: Electrochemistry > Topic: Variation of Conductivity with Concentration and Measurement

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Variation of Conductivity with Concentration and Measurement

A cell has E°cell = 0.52 V and an equilibrium constant of 10¹⁷ at 298 K. How many electrons are transferred?

E°cell = (0.059/n) log Kc , 0.52 = (0.059/n) × 17 , n = (1.003/0.52) ≈ 2 .

Ref: NCERT Class 12 Chemistry > Chapter 2: Electrochemistry > Topic: Variation of Conductivity with Concentration and Measurement

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Variation of Conductivity with Concentration and Measurement

A cell reaction has Δr G° = -285900 J/mol and involves 3 electrons at 298 K. What is the standard emf? (F = 96500 C/mol)

Δr G° = -n F E°cell , -285900 = -3 × 96500 × E°cell . E°cell = (285900/3 × 96500) = 0.987 V ≈ 0.99 V .

Ref: NCERT Class 12 Chemistry > Chapter 2: Electrochemistry > Topic: Variation of Conductivity with Concentration and Measurement

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Nernst Equation and Gibbs Energy and Equilibrium Constant

What is the cell potential at 298 K for Zn(s) | Zn²⁺(0.01 M) || Cu²⁺(0.1 M) | Cu(s) ? (Given: E°cell = 1.10 V )

Ecell = E°cell - (0.059/2) log ([Zn²⁺]/[Cu²⁺]) = 1.10 - (0.059/2) log (0.01/0.1) = 1.129 V .

Ref: NCERT Class 12 Chemistry > Chapter 2: Electrochemistry > Topic: Nernst Equation and Gibbs Energy and Equilibrium Constant

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Nernst Equation and Gibbs Energy and Equilibrium Constant

A cell Ni(s) | Ni²⁺(0.002 M) || Cl₂(g)(0.5 atm) | Cl⁻(0.05 M) | Pt(s) operates at 298 K. What is the cell potential? (Gi

E°cell = 1.36 - (-0.25) = 1.61 V . Ecell = 1.61 - (0.059/2) log ([Ni²⁺][Cl⁻]²/PCl_₂) = 1.61 - 0.0295 log (0.002 × 0.0025/0.5) = 1.61 + 0.084 = 1.694 V .

Ref: NCERT Class 12 Chemistry > Chapter 2: Electrochemistry > Topic: Nernst Equation and Gibbs Energy and Equilibrium Constant

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Nernst Equation and Gibbs Energy and Equilibrium Constant

In a fuel cell operating at 298 K, the cell potential decreases from 1.23 V to 1.17 V when the [H⁺] at the cathode incre

Δ E = -(0.059/n) log ([H⁺]₂/[H⁺]₁) , 1.17 - 1.23 = -0.06 = -(0.059/n) log (1/0.1) . -0.06 = -(0.059/n) × 1 , n = (0.059/0.06) ≈ 1 , but cathode reaction O₂ + 4H⁺ + 4e⁻ , so n = 4 .

Ref: NCERT Class 12 Chemistry > Chapter 2: Electrochemistry > Topic: Nernst Equation and Gibbs Energy and Equilibrium Constant

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Nernst Equation and Gibbs Energy and Equilibrium Constant

A galvanic cell has E°cell = 0.62 V . If the cell potential becomes 0.68 V at 298 K when [Oxidized] = 0.01 M and [Reduce

Ecell = E°cell - (0.059/n) log ([Ox]/[Red]) , 0.68 = 0.62 - (0.059/n) log (0.01/0.1) . 0.06 = (0.059/n) × 1 , n = (0.059/0.06) ≈ 1 .

Ref: NCERT Class 12 Chemistry > Chapter 2: Electrochemistry > Topic: Nernst Equation and Gibbs Energy and Equilibrium Constant

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Nernst Equation and Gibbs Energy and Equilibrium Constant

A cell Ni(s) | Ni²⁺(0.001 M) || Cl₂(g)(2 atm) | Cl⁻(0.1 M) | Pt(s) operates at 298 K. What is the cell potential? (Given

E°cell = 1.36 - (-0.25) = 1.61 V . Ecell = 1.61 - (0.059/2) log ([Ni²⁺][Cl⁻]²/PCl_₂) = 1.61 - 0.0295 log (0.001 × 0.01/2) = 1.61 + 0.103 = 1.713 V .

Ref: NCERT Class 12 Chemistry > Chapter 2: Electrochemistry > Topic: Nernst Equation and Gibbs Energy and Equilibrium Constant

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