From Paper 1: Advanced Inorganic and Physical Chemistry
5(b)6 marks
1.20 g of brass was dissolved in nitric acid, neutralised and made up to 250 cm³. 25.0 cm³ portions were added to excess KI. The iodine released needed 13.20 cm³ of 0.100 mol dm⁻³ sodium thiosulfate.
2Cu²⁺ + 4I⁻ → 2CuI + I₂
I₂ + 2S₂O₃²⁻ → 2I⁻ + S₄O₆²⁻
Calculate the percentage by mass of copper in the brass.
From Paper 1: Advanced Inorganic and Physical Chemistry
10(a)3 marks
Calculate E°cell for a cell made from Ag⁺/Ag (+0.80 V) and Fe²⁺/Fe (−0.44 V), and write the overall cell reaction.
From Paper 1: Advanced Inorganic and Physical Chemistry
10(b)3 marks
Explain why a reaction with a positive E°cell may not be observed in practice.
From Paper 3: General and Practical Principles in Chemistry
6(a)4 marks
An iron tablet containing iron(II) sulfate was dissolved in dilute sulfuric acid and titrated with 0.0100 mol dm⁻³ KMnO₄. The titre was 21.50 cm³. Calculate the mass of iron in the tablet.
From Paper 3: General and Practical Principles in Chemistry
106 marks
Describe how to measure the standard electrode potential of the Cu²⁺/Cu half-cell, including the conditions.
Score 0 / 22 · 0 of 5 marked
This paper is written by Plasmo in the style of the Edexcel A-Level Chemistry exam. It is not a past paper and is not produced or endorsed by the exam board.
Redox II Exam Questions: Edexcel A-Level Chemistry | Plasmo