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Consider the following reaction, Cu|Cu...

Consider the following reaction,
`Cu|Cu^(2+) (1M)||(Zn^(2+)(1 M)|Zn`
A cell represented above should have emf

A

positive

B

negative

C

zero

D

Cannot be predicted

Text Solution

AI Generated Solution

The correct Answer is:
To determine the EMF (Electromotive Force) of the electrochemical cell represented by the notation `Cu|Cu^(2+) (1M)||(Zn^(2+)(1 M)|Zn`, we will follow these steps: ### Step 1: Identify the Half-Reactions In the given cell, we have two half-reactions: 1. **Reduction at the Cathode (Copper)**: \[ Cu^{2+} + 2e^- \rightarrow Cu \quad (E^\circ_{Cu} = +0.34 \, V) \] 2. **Oxidation at the Anode (Zinc)**: \[ Zn \rightarrow Zn^{2+} + 2e^- \quad (E^\circ_{Zn} = -0.76 \, V) \] ### Step 2: Write the Cell Notation The cell notation indicates that copper is being reduced (gaining electrons) and zinc is being oxidized (losing electrons). ### Step 3: Calculate the Standard EMF of the Cell The standard EMF (E°) of the cell can be calculated using the formula: \[ E^\circ_{cell} = E^\circ_{cathode} - E^\circ_{anode} \] Substituting the values: \[ E^\circ_{cell} = E^\circ_{Cu} - E^\circ_{Zn} = 0.34 \, V - (-0.76 \, V) \] \[ E^\circ_{cell} = 0.34 \, V + 0.76 \, V = 1.10 \, V \] ### Step 4: Apply the Nernst Equation The Nernst equation is used to calculate the EMF under non-standard conditions: \[ E = E^\circ - \frac{0.059}{n} \log \left( \frac{[products]}{[reactants]} \right) \] Where: - \( n \) = number of moles of electrons transferred (which is 2 in this case). - The concentrations of both \( Cu^{2+} \) and \( Zn^{2+} \) are given as 1 M. ### Step 5: Substitute Values into the Nernst Equation Since both concentrations are 1 M, the reaction quotient \( Q \) becomes: \[ Q = \frac{[Cu^{2+}]}{[Zn^{2+}]} = \frac{1}{1} = 1 \] Thus, \( \log(1) = 0 \). Substituting into the Nernst equation: \[ E = 1.10 \, V - \frac{0.059}{2} \cdot 0 \] \[ E = 1.10 \, V \] ### Conclusion The EMF of the cell is: \[ \text{EMF} = 1.10 \, V \]

To determine the EMF (Electromotive Force) of the electrochemical cell represented by the notation `Cu|Cu^(2+) (1M)||(Zn^(2+)(1 M)|Zn`, we will follow these steps: ### Step 1: Identify the Half-Reactions In the given cell, we have two half-reactions: 1. **Reduction at the Cathode (Copper)**: \[ Cu^{2+} + 2e^- \rightarrow Cu \quad (E^\circ_{Cu} = +0.34 \, V) \] ...
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