For the electrochemical cell, Zn(s) | Zn ²⁺(0.1 M ) || H ^+( pH = x) | H ₂(1 atm ) | Pt the measured cell potential is 0.61 V at 298 K . The value of x is ____. [ Given: E^ _ Zn ²⁺/ Zn = -0.76 V , E^ _ H ^+/ H ₂ = 0 V and 2.303RT F = 0.06 V

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For the electrochemical cell, Zn(s) | Zn ²⁺(0.1 M ) || H ^+( pH = x) | H ₂(1 atm ) | Pt the measured cell potential is 0.61 V at 298 K . The value of x is ____. [ Given: E^ _ Zn ²⁺/ Zn = -0.76 V , E^ _ H ^+/ H ₂ = 0 V and 2.303RT F = 0.06 V ]

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Correct answer: 3

The cell reaction is: Zn(s) + 2 H ^+( aq ) Zn ²⁺( aq ) + H ₂( g ) Number of electrons transferred, n = 2 . Standard cell potential: E^ _ cell = E^ _ cathode - E^ _ anode = 0 - (-0.76) = 0.76 V Applying the Nernst equation: E_ cell = E^ _ cell - 0.06 2 [ Zn ²⁺]P_ H ₂ [ H ^+]^2 0.61 = 0.76 - 0.03 0.1 1 (10^ -x )^2 0.61 = 0.76 - 0.03 (10^ 2x-1 ) 0.61 = 0.76 - 0.03(2x - 1) 0.61 = 0.76 - 0.06x + 0.03 0.61 = 0.79 - 0.06x 0.06x = 0.18 x = 3 Answer: 3

For the electrochemical cell, Zn(s) | Zn ²⁺(0.1 M ) || H ^+( pH = x) | H ₂(1 atm ) | Pt the measured cell potential is 0.61 V at 298 K . The value of x is ____. [ Given: E^ _ Zn ²⁺/ Zn = -0.76 V , E^ _ H ^+/ H ₂ = 0 V and 2.303RT F = 0.06 V ]

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