# Sample problems voltaic cells

1. Question: The standard reduction potential for Cu²⁺ to Cu is +0.34 V and for Zn²⁺ to Zn is -0.76 V. What is the EMF of the voltaic cell? Solution: E₀cell = E₀cathode – E₀anode = 0.34 V – (-0.76 V) = 1.1 V

2. Question: A voltaic cell is constructed with a Mg/Mg²⁺ half-cell and a Ag/Ag⁺ half-cell. The standard reduction potentials are -2.37 V and 0.80 V respectively. What is the cell potential? Solution: E₀cell = E₀cathode – E₀anode = 0.80 V – (-2.37 V) = 3.17 V
3. Question: In a voltaic cell, the reduction potential for the reaction M⁴⁺ + 4e⁻ → M is -1.50 V and the oxidation potential for the reaction X → X³⁺ + 3e⁻ is -0.60 V. Calculate the cell potential. Solution: E₀cell = E₀cathode – E₀anode = -1.50 V – (-0.60 V) = -0.90 V
4. Question: What is the cell potential for a voltaic cell composed of a Fe/Fe²⁺ half-cell (E⁰ = -0.44 V) and a Zn/Zn²⁺ half-cell (E⁰ = -0.76 V)? Solution: E₀cell = E₀cathode – E₀anode = -0.44 V – (-0.76 V) = 0.32 V
5. Question: Calculate the cell potential for a voltaic cell where the cathode reaction is Ni²⁺ + 2e⁻ → Ni (E⁰ = -0.25 V) and the anode reaction is Zn → Zn²⁺ + 2e⁻ (E⁰ = -0.76 V). Solution: E₀cell = E₀cathode – E₀anode = -0.25 V – (-0.76 V) = 0.51 V
6. Question: A voltaic cell consists of a standard hydrogen electrode and a standard silver electrode. Given that the standard reduction potentials for H⁺ and Ag⁺ are 0.00 V and +0.80 V respectively, calculate the cell potential. Solution: E₀cell = E₀cathode – E₀anode = 0.80 V – 0.00 V = 0.80 V
7. Question: What is the cell potential for a voltaic cell composed of a Ag/Ag⁺ half-cell (E⁰ = 0.80 V) and a Cu/Cu²⁺ half-cell (E⁰ = 0.34 V)? Solution: E₀cell = E₀cathode – E₀anode = 0.80 V – 0.34 V = 0.46 V
8. Question: Calculate the cell potential for a voltaic cell where the cathode reaction is Ni²⁺ + 2e⁻ → Ni (E⁰ = -0.25 V) and the anode reaction is Mg → Mg²⁺ + 2e⁻ (E⁰ = -2.37 V). Solution: E₀cell = E₀cathode – E₀anode = -0.25 V – (-2.37 V) = 2.12 V
9. Question: In a voltaic cell, the reduction potential for the reaction M³⁺ + 3e⁻ → M is -1.50 V and the oxidation potential for the reaction X → X⁴⁺ + 4e⁻ is -0.60 V. Calculate the cell potential. Solution: E₀cell = E₀cathode – E₀anode = -1.50 V – (-0.60 V) = -0.90 V
10. Question: A voltaic cell is constructed with a Al/Al³⁺ half-cell and a Zn/Zn²⁺ half-cell. The standard reduction potentials are -1.66 V and -0.76 V respectively. What is the cell potential? Solution: E₀cell = E₀cathode – E₀anode = -0.76 V – (-1.66 V) = 0.90 V