Photo AI
Table 4 shows some electrode half-equations and their standard electrode potentials - AQA - A-Level Chemistry - Question 10 - 2017 - Paper 1
Question 10
Table 4 shows some electrode half-equations and their standard electrode potentials. Electrode half-equation E° / V Cl2(g) + 2e⁻ → 2Cl⁻(aq) ... show full transcript
Worked Solution & Example Answer:Table 4 shows some electrode half-equations and their standard electrode potentials - AQA - A-Level Chemistry - Question 10 - 2017 - Paper 1
Step 1
Step 2
Step 3
Step 4
Use data from Table 4 to identify an acid that will oxidise copper.
Answer
An acid that will oxidise copper is nitric acid (HNO3).
Explanation: Nitric acid is a stronger oxidizing agent as it contains NO3⁻ which can readily react with copper.
Balanced Equation: 3Cu + 8H⁺ + 2NO3⁻ → 3Cu²⁺ + 2NO + 4H2O
EMF Calculation: The overall EMF for the reaction is calculated as follows:
For the half-reactions:
- Cu²⁺ + 2e⁻ → Cu (E° = +0.34 V)
- 2NO3⁻ + 4H⁺ + 2e⁻ → NO(g) + 2H2O (E° = +0.96 V)
Combining these, we get:
EMF = (E° for reduction) - (E° for oxidation) = 0.96 V - 0.34 V = 0.62 V.