Calculate the voltage of following electrochemical cell under standard conditions. Name anode and cathode in each cell. (i) Zn - Ag (ii) Co - Ni. The standard reduction potentials of various half cells are:
`Zn^(2+)//Zn =-0.76V, Ag^(+)//Ag= +0.80V`
`Co^(2+)//Co = -0.28V, Ni^(2+)//Ni= -0.25V`

Explanation

To calculate the voltage of the given electrochemical cells under standard conditions and to identify the anode and cathode for each cell, we can follow these steps:

### Step 1: Identify the half-reactions and their standard reduction potentials
For the first cell (Zn - Ag):
- **Zn^(2+) + 2e^- → Zn** (E° = -0.76 V)
- **Ag^+ + e^- → Ag** (E° = +0.80 V)

For the second cell (Co - Ni):
- **Co^(2+) + 2e^- → Co** (E° = -0.28 V)
- **Ni^(2+) + 2e^- → Ni** (E° = -0.25 V)

### Step 2: Determine the anode and cathode
The anode is where oxidation occurs (the half-reaction with the lower reduction potential), and the cathode is where reduction occurs (the half-reaction with the higher reduction potential).

For the first cell (Zn - Ag):
- **Anode**: Zn (E° = -0.76 V)
- **Cathode**: Ag (E° = +0.80 V)

For the second cell (Co - Ni):
- **Anode**: Co (E° = -0.28 V)
- **Cathode**: Ni (E° = -0.25 V)

### Step 3: Calculate the cell voltage (E°cell)
The formula to calculate the standard cell potential (E°cell) is:
\[ E°_{cell} = E°_{cathode} - E°_{anode} \]

For the first cell (Zn - Ag):
\[ E°_{cell} = E°_{Ag} - E°_{Zn} \]
\[ E°_{cell} = (+0.80 \, V) - (-0.76 \, V) \]
\[ E°_{cell} = +0.80 \, V + 0.76 \, V \]
\[ E°_{cell} = +1.56 \, V \]

For the second cell (Co - Ni):
\[ E°_{cell} = E°_{Ni} - E°_{Co} \]
\[ E°_{cell} = (-0.25 \, V) - (-0.28 \, V) \]
\[ E°_{cell} = -0.25 \, V + 0.28 \, V \]
\[ E°_{cell} = +0.03 \, V \]

### Final Results
- For the Zn - Ag cell:
- **Anode**: Zn
- **Cathode**: Ag
- **Voltage**: +1.56 V

- For the Co - Ni cell:
- **Anode**: Co
- **Cathode**: Ni
- **Voltage**: +0.03 V