Answer: Na reacts more vigorously with water than Li, despite Li's more negative E°, due to kinetic factors.
- A Na reacts more vigorously with water than Li, despite Li's more negative E°, due to kinetic factors
- B Lithium instead reacts noticeably faster with water than sodium does in practice
- C Both metals react with cold water at an identical and equally vigorous observable rate
- D The standard electrode potential value alone fully and accurately predicts the reaction rate
Correct answer: A. Na reacts more vigorously with water than Li, despite Li's more negative E°, due to kinetic factors
Explanation: Li's high hydration enthalpy means thermodynamics favours Li strongly, but a thin film of LiOH coats Li and slows the reaction kinetically; Na's film is more reactive/less coherent.
Each s-block metal ion emits a characteristic flame colour because heating excites electrons to higher energy levels; light is emitted as they fall back, with the colour determined by the specific energy gap.
Concept context
Group 1 (alkali metals) and Group 2 (alkaline earth metals). Learn their reactions with water and air, important compounds like NaOH, Na₂CO₃, and CaCO₃, and anomalous behaviour of lithium and beryllium.