Standard Electrode Potentials
Study of trends in M²⁺/M and M³⁺/M²⁺ standard electrode potentials and their implications for chemical reactivity.
What is Standard Electrode Potentials?
The potential of an electrode measured under standard conditions (298 K, 1 atm pressure, 1 M concentration for solutions) relative to the Standard Hydrogen Electrode (SHE).
Key points
- Understand the factors influencing standard electrode potentials of transition metal ions.
- Analyze the trends in E°(M²⁺/M) and E°(M³⁺/M²⁺) across the first transition series.
- Relate these trends to the electronic configurations and stability of ions.
- Predict the relative oxidizing and reducing strengths of transition metal ions.
Common exam trap
Assuming a simple, monotonic trend in E° values across the transition series without considering electronic configurations.
Definitions
- Term
Standard Electrode Potential (E°)
- Meaning
The potential of an electrode measured under standard conditions (298 K, 1 atm pressure, 1 M concentration for solutions) relative to the Standard Hydrogen Electrode (SHE).
- Term
Hydration Enthalpy
- Meaning
The enthalpy change that occurs when one mole of gaseous ions is dissolved in water to form hydrated ions.
- Term
Ionization Enthalpy
- Meaning
The energy required to remove an electron from a neutral gaseous atom or ion.
Learning objectives
Understand the factors influencing standard electrode potentials of transition metal ions.
Analyze the trends in E°(M²⁺/M) and E°(M³⁺/M²⁺) across the first transition series.
Relate these trends to the electronic configurations and stability of ions.
Predict the relative oxidizing and reducing strengths of transition metal ions.
Prerequisites
Electronic configuration of transition elements
Thermodynamic concepts (enthalpy changes)
Redox reactions
Concept of standard electrode potential
Common mistakes
Assuming a simple, monotonic trend in E° values across the transition series without considering electronic configurations.
Confusing the trends for M²⁺/M with M³⁺/M²⁺ couples.
Overlooking the significant impact of stable electronic configurations (d⁵, d¹⁰) on electrode potentials.
Incorrectly predicting oxidizing/reducing strength based solely on atomic number.
Keywords
Standard Electrode Potential
Transition Elements
Redox Potential
Oxidation State
Hydration Enthalpy
Ionization Enthalpy
Electronic Configuration
Chemical Reactivity
First Transition Series
Manganese
Zinc
Practice preview
Which of the following transition metal ions is expected to have the highest standard electrode potential (E° value) for the M²⁺/M couple?…
easy
Which of the following statements is INCORRECT regarding the standard electrode potentials of transition metals?…
hard
Which of the following transition metals exhibits a very low standard electrode potential (E° value) for the M²⁺/M couple, indicating it is difficult to oxidize?…
easy