Electrochemistry: every question, 2016 to 2025

Notes: Electrochemical cells: Nernst equation, emf and electrodes (full notes) · short notes

Notes: Electrolytes: conductance, Kohlrausch, Debye–Hückel and transport numbers (full notes) · short notes

2025

• Q1(i) KCl salt bridge for a silver–lead cell5 marks Answered
• Q1(j) Equilibrium constant from standard potentials5 marks Answered
• Q7 ΔG° and ΔS° from emf; the iron cell10 marks Answered
• Q13 ΔfG° of M³⁺ and E° of M³⁺/M from thermal data20 marks Answered

2024

• Q1(i) Zinc–copper cell from two half-reactions5 marks Answered
• Q1(j) Alkaline (sodium) error of the glass electrode5 marks Answered
• Q11(c) Cell reaction and ΔG, ΔH, ΔS from emf and dE/dT5 marks Question only
• Q12(b) Potential of a silver electrode in saturated silver iodide10 marks Question only

2023

• Q1(i) E° of Na⁺/Na from ΔrH° and ΔrS°5 marks Answered
• Q1(j) pH from a calomel–quinhydrone cell5 marks Answered
• Q6(a) Emf of a hydrogen-electrode concentration cell5 marks Answered
• Q6(b) Types of reversible electrodes5 marks Answered
• Q14(a) Which pairs of Fe³⁺/Fe²⁺ and Sn⁴⁺/Sn²⁺ react10 marks Answered
• Q14(b) Spontaneous reaction: cell, E°cell and K at 298 K10 marks Answered

2022

• Q1(i) Nernst equation for the redox electrode Pt | Cr⁶⁺, Cr³⁺5 marks Answered
• Q1(j) Same electrode positive or negative5 marks Answered
• Q6(a) Lead–acid cell: electrode and cell reactions on discharge6 marks Answered
• Q6(b) Specific gravity of the acid as a test of the cell4 marks Answered

2021

• Q1(e) Electrophoretic effect in the Debye–Hückel–Onsager theory5 marks Answered
• Q1(i) Role of H₃PO₄ in the dichromate titration of Fe²⁺5 marks Answered
• Q1(j) Why a voltmeter does not give the EMF5 marks Answered
• Q6 ΔG, ΔH and ΔS of an all-solid cell reaction from emf10 marks Answered
• Q10(a) E° of Fe²⁺/Fe from two other couples5 marks Answered
• Q11(c) Temperature dependence of electrolytic and metallic conduction5 marks Question only
• Q13(a) pH of a solution with the hydrogen electrode10 marks Question only
• Q15(c) Why saturated KCl or NH₄NO₃ in a salt bridge5 marks Answered

2020

• Q1(f) Potassium sulfate activities5 marks Answered
• Q1(i) Electrochemical potential of zinc ions5 marks Answered
• Q1(j) Open-circuit emf and equilibrium5 marks Answered
• Q7(a) Thermodynamic parameters from emf5 marks Answered
• Q7(b) Enthalpy of the hydrogen–silver chloride cell5 marks Answered
• Q14(a) Zn | ZnCl₂ | AgCl | Ag: reactions, transference, E° and K10 marks Question only
• Q14(b) Ksp of AgI from a concentration cell10 marks Question only

2019

• Q1(g) Single-ion activity coefficients5 marks Answered
• Q1(l) Iron redox-electrode potential5 marks Answered
• Q8(b) Iron–silver cell5 marks Answered
• Q13(b) Potassium-ion drift velocity5 marks Answered
• Q15(a) Why KCl, not NaCl, in a salt bridge5 marks Question only

2018

• Q1(l) Conductivity as an intensive property5 marks Answered
• Q9(a) Transport number of H⁺ falls with temperature5 marks Question only
• Q9(b) Molar conductivity of KClO₄ solution5 marks Question only
• Q11(b) EMF of Zn | ZnCl₂(m) | AgCl, Ag in terms of γ±5 marks Question only

2017

• Q8(b) Zinc–copper galvanic cell5 marks Answered
• Q13(a) Debye–Huckel law and ionic strength10 marks Answered
• Q15(b) High proton transport number8 marks Answered

2016

• Q1(k) Electrolysis of copper sulfate5 marks Answered