For the electrochemical cell: Mg(s) | Mg²⁺(aq, 1M) || Cu²⁺(aq, 1M) | Cu(s) The standard EMF of the cell is 2.70 V at 300 K . When the concentration of Mg²⁺ is changed to 10 M , the cell potential chan

Question

For the electrochemical cell:

Mg(s) | Mg²⁺(aq, 1M) || Cu²⁺(aq, 1M) | Cu(s)

The standard EMF of the cell is $2.70 V$ at $300 K$ . When the concentration of Mg²⁺ is changed to $10 M$ , the cell potential changes to $x V$ at $300 K$ . The value of $x$ is _______. (Given, $\frac{F}{R} = 11500 K V^{- 1}$ , where $F$ is the Faraday constant and $R$ is the gas constant, $ln (10) = 2.30$ )

TestHub · Accepted Answer

Anode: Mg ( s ) ⟶ Mg 2 + ( aq ) + 2 e − Cathode: Cu 2 + ( aq ) + 2 e − ​ ⟶ Cu ( s ) Q = [ Cu 2 + ] [ Mg 2 + ] ​ = 1 10 ​ E cell ​ = ​ 2.70 − 2 × F 2.3 × R × T ​ lo g 10 ​ ​ ​ ​ ​ = 2.70 − 11500 × 2 2.3 × 300 ​ = 2.70 − 115 × 2 2.3 × 3 ​ = 2.70 − 0.03 = 2.67 V

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