State the meaning of the term electrochemical series. The electrochemical series is a list of electrode potentials arranged in numerical order. It indicates the likelihood of a species to gain or lose electrons, thus determining its tendency to be oxidized or reduced in an electrochemical reaction.

A-Level AQA Chemistry Electrode Potentials & Electrochemical Cells: State the meaning of the term el

State the meaning of the term electrochemical series - AQA - A-Level Chemistry - Question 8 - 2021 - Paper 1

Question 8

State the meaning of the term electrochemical series. The electrochemical series is a list of electrode potentials arranged in numerical order. It indicates the lik... show full transcript

Worked Solution & Example Answer:State the meaning of the term electrochemical series - AQA - A-Level Chemistry - Question 8 - 2021 - Paper 1

Step 1

State two conditions needed for the following half-cell to have E°' = 0.00 V

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Answer

The concentration of the reactants and products must be 1 M.
The temperature must be maintained at 25°C.

Step 2

Identify the weakest reducing agent in Table 8.

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Answer

The weakest reducing agent in Table 8 is [Co(H2O)6]3+.

Step 3

Use half-equations from Table 8 to deduce an equation for the reduction of VO2+ to form VO2+ in aqueous solution by iron.

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Answer

The reduction equation can be expressed as:

$3 ext{VO}_2^+ + 2 ext{Fe} \rightarrow 3 ext{VO}^{2+} + 2 ext{Fe}^{3+}$

Step 4

Use data from Table 8 to explain why [Co(H2O)6]3+(aq) will undergo a redox reaction with [Fe(H2O)6]2+(aq)

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Answer

The electrochemical potentials indicated in Table 8 show that [Co(H2O)6]3+ has a higher potential than [Fe(H2O)6]2+. Therefore, it can oxidize [Fe(H2O)6]2+ to [Fe(H2O)6]3+.

Equation

$ext{Co(H}_2 ext{O)}_6^{3+} + ext{Fe(H}_2 ext{O)}_6^{2+} \rightarrow ext{Co(H}_2 ext{O)}_6^{2+} + ext{Fe(H}_2 ext{O)}_6^{3+}$

Step 5

Suggest why the two cobalt(III) complex ions in Table 8 have different electrode potentials.

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Answer

The different ligand environments around the cobalt(III) ions affect their stability and reactivity. Ligands with different coordinating abilities or electron-donating properties can alter the electrode potential of the cobalt ions.

State the meaning of the term electrochemical series - AQA - A-Level Chemistry - Question 8 - 2021 - Paper 1

Worked Solution & Example Answer:State the meaning of the term electrochemical series - AQA - A-Level Chemistry - Question 8 - 2021 - Paper 1

State two conditions needed for the following half-cell to have E°' = 0.00 V

Identify the weakest reducing agent in Table 8.

Use half-equations from Table 8 to deduce an equation for the reduction of VO2+ to form VO2+ in aqueous solution by iron.

Use data from Table 8 to explain why [Co(H2O)6]3+(aq) will undergo a redox reaction with [Fe(H2O)6]2+(aq)

Equation

Suggest why the two cobalt(III) complex ions in Table 8 have different electrode potentials.

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