At 25°C, find the emf in volts to 3 decimals of Ag | AgBr(s) | Br⁻(a = 0.20), Cu²⁺(a = 0.48), Cu⁺(a = 0.24) | Pt. Standard cell emf is 0.082 V; R = 8.314 J/(mol K), F = 96500 C/mol.
The left electrode oxidizes Ag in the presence of bromide, while Cu²⁺ reduces to Cu⁺ on the right. The net reaction quotient is $Q=a_{Cu^+}/(a_{Cu^{2+}}a_{Br^-})=0.24/(0.48\times0.20)=2.5$, with one transferred electron. Nernst gives $E=0.082-(RT/F)\ln2.5\approx0.0585$ V, rounding to 0.058–0.059 depending on the temperature convention; the original 0.058–0.060 interval is retained.
More Electrochemistry: Standard electrode potential and electrochemical cells. Nernst Equation and its application, relationship between electrode potential and thermodynamic quantities, Potentiometric and conductometric titrations. Ionic mobility and conductivity. Kohlrausch’s law, Debye-Hückel limiting law. Debye-Hückel- Onsager equation. questions
GATE 2019 CY Q59– For the cell M(s) MI₂(s) MI₂(aq) M(s), standard reduction potentials at 298 K are…
GATE 2025 CY Q63– For the cell reaction, Hg 2Cl 2(s)+H 2(1\ atm)2Hg(l)+2H+(a=1)+2Cl-(a=1) The standard cell…
GATE 2026 CY Q35– The ionic mobility of Ag+ in very dilute aqueous AgNO3 at 298 K is y10-8 m² V−1 s−1. The…
GATE 2026 CY Q47– For the following electrochemical cells, liquid junction potentials affect the cell…
GATE 2026 CY Q63– A calibrated glass-electrode/standard-calomel pH meter measures 0.814 V for pH 4.01 at 25…
GATE 2023 CY Q62– By the Debye–Hückel limiting law, the mean molal activity coefficient of 0.87 g K 2SO 4…