DP Chemistry (first assessment 2025)

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Question 21M.1A.HL.TZ2.30

Date	May 2021	Marks available	[Maximum mark: 1]	Reference code	21M.1A.HL.TZ2.30
Level	HL	Paper	1A	Time zone	TZ2
Command term	Solve	Question number	30	Adapted from	N/A

30.

[Maximum mark: 1]

21M.1A.HL.TZ2.30

What would be the electrode potential, E^⦵, of the Mn²⁺(aq)|Mn (s) half-cell if Fe³⁺(aq)|Fe²⁺(aq) is used as the reference standard?

Mn²⁺ (aq) + 2e⁻ $⇌$ Mn (s) E^⦵ = −1.18 V

Fe³⁺ (aq) + e⁻ $⇌$ Fe²⁺(aq) E^⦵ = +0.77 V

A. −1.95 V

B. −0.41 V

C. +0.41 V

D. +1.95 V

[1]

Markscheme

A

Syllabus sections

Reactivity 3. What are the mechanisms of chemical change? » Reactivity 3.2—Electron transfer reactions » Reactivity 3.2.13—Standard cell potential, E⦵cell, can be calculated from standard electrode potentials. E⦵cell has a positive value for a spontaneous reaction. Predict whether a reaction is spontaneous in the forward or reverse direction from E⦵ data.