Topic 16: Redox Equilibria

Understand the terms ‘oxidation’ and ‘reduction’ in terms of electron transfer and changes in oxidation number, applied to s-, p- and d-block elements.

Use —the terms ‘oxidation’ and ‘reduction’ in terms of electron transfer and changes in oxidation number, applied to s-, p- to connect the rule to the data and decision in the question.

This matters because —the terms ‘oxidation’ and ‘reduction’ in terms of electron transfer and changes in oxidation number, applied to s-, p- determines what can be inferred or chosen; begin with the stated conditions and keep the conclusion tied to the evidence.

Example: apply —the terms ‘oxidation’ and ‘reduction’ in terms of electron transfer and changes in oxidation number, applied to s-, p- to one small, clearly defined case, show the key step or comparison, and explain the result in words.

Boundary: —The terms ‘oxidation’ and ‘reduction’ in terms of electron transfer and changes in oxidation number, applied to s-, p- is not a universal recommendation. Check the syllabus scope, assumptions, units and the limits of the evidence before generalising.

Know what is meant by the term ‘standard electrode potential’, Eo.

Use —what is meant by the term ‘standard electrode potential’, eo to connect the rule to the data and decision in the question.

This matters because —what is meant by the term ‘standard electrode potential’, eo determines what can be inferred or chosen; begin with the stated conditions and keep the conclusion tied to the evidence.

Example: apply —what is meant by the term ‘standard electrode potential’, eo to one small, clearly defined case, show the key step or comparison, and explain the result in words.

Boundary: —What is meant by the term ‘standard electrode potential’, Eo is not a universal recommendation. Check the syllabus scope, assumptions, units and the limits of the evidence before generalising.

Know that the standard electrode potential, Eo, is measured in conditions of: i 298 K temperature ii 100 kPa pressure of gases iii 1.00 mol dm-3 concentration of ions.

Use —the standard electrode potential, eo, is measured in conditions of: i 298 k temperature ii 100 kpa pressure of gases iii to connect the rule to the data and decision in the question.

This matters because —the standard electrode potential, eo, is measured in conditions of: i 298 k temperature ii 100 kpa pressure of gases iii determines what can be inferred or chosen; begin with the stated conditions and keep the conclusion tied to the evidence.

Example: apply —the standard electrode potential, eo, is measured in conditions of: i 298 k temperature ii 100 kpa pressure of gases iii to one small, clearly defined case, show the key step or comparison, and explain the result in words.

Boundary: —The standard electrode potential, Eo, is measured in conditions of: i 298 K temperature ii 100 kPa pressure of gases iii is not a universal recommendation. Check the syllabus scope, assumptions, units and the limits of the evidence before generalising.

Know the features of the standard hydrogen electrode and understand why a reference electrode is necessary.

Use —the features of the standard hydrogen electrode and understand why a reference electrode is necessary to connect the rule to the data and decision in the question.

This matters because —the features of the standard hydrogen electrode and understand why a reference electrode is necessary determines what can be inferred or chosen; begin with the stated conditions and keep the conclusion tied to the evidence.

Example: apply —the features of the standard hydrogen electrode and understand why a reference electrode is necessary to one small, clearly defined case, show the key step or comparison, and explain the result in words.

Boundary: —The features of the standard hydrogen electrode and understand why a reference electrode is necessary is not a universal recommendation. Check the syllabus scope, assumptions, units and the limits of the evidence before generalising.

Understand that different methods are used to measure standard electrode potentials of: i metals or non-metals in contact with their ions in aqueous solution ii ions of the same element with different oxidation numbers.

Use —different methods are used to measure standard electrode potentials of: i metals or non-metals in contact with their ions to connect the rule to the data and decision in the question.

This matters because —different methods are used to measure standard electrode potentials of: i metals or non-metals in contact with their ions determines what can be inferred or chosen; begin with the stated conditions and keep the conclusion tied to the evidence.

Example: apply —different methods are used to measure standard electrode potentials of: i metals or non-metals in contact with their ions to one small, clearly defined case, show the key step or comparison, and explain the result in words.

Boundary: —Different methods are used to measure standard electrode potentials of: i metals or non-metals in contact with their ions is not a universal recommendation. Check the syllabus scope, assumptions, units and the limits of the evidence before generalising.

CORE PRACTICAL 12 Investigating some electrochemical cells.

Use —core practical 12 investigating some electrochemical cells to connect the rule to the data and decision in the question.

This matters because —core practical 12 investigating some electrochemical cells determines what can be inferred or chosen; begin with the stated conditions and keep the conclusion tied to the evidence.

Example: apply —core practical 12 investigating some electrochemical cells to one small, clearly defined case, show the key step or comparison, and explain the result in words.

Boundary: —CORE PRACTICAL 12 Investigating some electrochemical cells is not a universal recommendation. Check the syllabus scope, assumptions, units and the limits of the evidence before generalising.

Be able to calculate a standard emf, Eocell , by combining two standard electrode potentials.

Use —a standard emf, eocell , by combining two standard electrode potentials to connect the rule to the data and decision in the question.

This matters because —a standard emf, eocell , by combining two standard electrode potentials determines what can be inferred or chosen; begin with the stated conditions and keep the conclusion tied to the evidence.

Example: apply —a standard emf, eocell , by combining two standard electrode potentials to one small, clearly defined case, show the key step or comparison, and explain the result in words.

Boundary: —A standard emf, Eocell , by combining two standard electrode potentials is not a universal recommendation. Check the syllabus scope, assumptions, units and the limits of the evidence before generalising.

Be able to write cell diagrams using the conventional representation of half-cells.

Use —write cell diagrams using the conventional representation of half-cells to connect the rule to the data and decision in the question.

This matters because —write cell diagrams using the conventional representation of half-cells determines what can be inferred or chosen; begin with the stated conditions and keep the conclusion tied to the evidence.

Example: apply —write cell diagrams using the conventional representation of half-cells to one small, clearly defined case, show the key step or comparison, and explain the result in words.

Boundary: —Write cell diagrams using the conventional representation of half-cells is not a universal recommendation. Check the syllabus scope, assumptions, units and the limits of the evidence before generalising.

Understand the importance of the conditions when measuring an electrode potential, E.

Use —the importance of the conditions when measuring an electrode potential, e to connect the rule to the data and decision in the question.

This matters because —the importance of the conditions when measuring an electrode potential, e determines what can be inferred or chosen; begin with the stated conditions and keep the conclusion tied to the evidence.

Example: apply —the importance of the conditions when measuring an electrode potential, e to one small, clearly defined case, show the key step or comparison, and explain the result in words.

Boundary: —The importance of the conditions when measuring an electrode potential, E is not a universal recommendation. Check the syllabus scope, assumptions, units and the limits of the evidence before generalising.

Be able to use standard electrode potentials to predict the thermodynamic feasibility of a reaction.

Use —standard electrode potentials to predict the thermodynamic feasibility of a reaction to connect the rule to the data and decision in the question.

This matters because —standard electrode potentials to predict the thermodynamic feasibility of a reaction determines what can be inferred or chosen; begin with the stated conditions and keep the conclusion tied to the evidence.

Example: apply —standard electrode potentials to predict the thermodynamic feasibility of a reaction to one small, clearly defined case, show the key step or comparison, and explain the result in words.

Boundary: —Standard electrode potentials to predict the thermodynamic feasibility of a reaction is not a universal recommendation. Check the syllabus scope, assumptions, units and the limits of the evidence before generalising.

Understand that Eocell is directly proportional to the total entropy change and to lnK for a reaction.

Use —eocell is directly proportional to the total entropy change and to lnk for a reaction to connect the rule to the data and decision in the question.

This matters because —eocell is directly proportional to the total entropy change and to lnk for a reaction determines what can be inferred or chosen; begin with the stated conditions and keep the conclusion tied to the evidence.

Example: apply —eocell is directly proportional to the total entropy change and to lnk for a reaction to one small, clearly defined case, show the key step or comparison, and explain the result in words.

Boundary: —Eocell is directly proportional to the total entropy change and to lnK for a reaction is not a universal recommendation. Check the syllabus scope, assumptions, units and the limits of the evidence before generalising.

Understand the limitations of predictions made using standard electrode potentials, in terms of kinetic stability of systems and departure from standard conditions.

Use —the limitations of predictions made using standard electrode potentials, in terms of kinetic stability of systems to connect the rule to the data and decision in the question.

This matters because —the limitations of predictions made using standard electrode potentials, in terms of kinetic stability of systems determines what can be inferred or chosen; begin with the stated conditions and keep the conclusion tied to the evidence.

Example: apply —the limitations of predictions made using standard electrode potentials, in terms of kinetic stability of systems to one small, clearly defined case, show the key step or comparison, and explain the result in words.

Boundary: —The limitations of predictions made using standard electrode potentials, in terms of kinetic stability of systems is not a universal recommendation. Check the syllabus scope, assumptions, units and the limits of the evidence before generalising.

Know that standard electrode potentials are sometimes referred to as standard reduction potentials and can be listed as an electrochemical series.

Use —standard electrode potentials are sometimes referred to as standard reduction potentials and can be listed as to connect the rule to the data and decision in the question.

This matters because —standard electrode potentials are sometimes referred to as standard reduction potentials and can be listed as determines what can be inferred or chosen; begin with the stated conditions and keep the conclusion tied to the evidence.

Example: apply —standard electrode potentials are sometimes referred to as standard reduction potentials and can be listed as to one small, clearly defined case, show the key step or comparison, and explain the result in words.

Boundary: —Standard electrode potentials are sometimes referred to as standard reduction potentials and can be listed as is not a universal recommendation. Check the syllabus scope, assumptions, units and the limits of the evidence before generalising.

Understand how standard electrode potentials can be used to predict the thermodynamic feasibility of disproportionation reactions.

Use —how standard electrode potentials can be used to predict the thermodynamic feasibility of disproportionation reactions to connect the rule to the data and decision in the question.

This matters because —how standard electrode potentials can be used to predict the thermodynamic feasibility of disproportionation reactions determines what can be inferred or chosen; begin with the stated conditions and keep the conclusion tied to the evidence.

Example: apply —how standard electrode potentials can be used to predict the thermodynamic feasibility of disproportionation reactions to one small, clearly defined case, show the key step or comparison, and explain the result in words.

Boundary: —How standard electrode potentials can be used to predict the thermodynamic feasibility of disproportionation reactions is not a universal recommendation. Check the syllabus scope, assumptions, units and the limits of the evidence before generalising.

Be able to carry out both structured and unstructured titration calculations involving redox reactions, including iron(II) ions and potassium manganate(VII) and sodium thiosulfate and iodine.

Use —carry out both structured and unstructured titration calculations involving redox reactions to connect the rule to the data and decision in the question.

This matters because —carry out both structured and unstructured titration calculations involving redox reactions determines what can be inferred or chosen; begin with the stated conditions and keep the conclusion tied to the evidence.

Example: apply —carry out both structured and unstructured titration calculations involving redox reactions to one small, clearly defined case, show the key step or comparison, and explain the result in words.

Boundary: —Carry out both structured and unstructured titration calculations involving redox reactions is not a universal recommendation. Check the syllabus scope, assumptions, units and the limits of the evidence before generalising.

Be able to discuss the uncertainty of measurements and their implications for the validity of the final results.

Use —discuss the uncertainty of measurements and their implications for the validity of the final results to connect the rule to the data and decision in the question.

This matters because —discuss the uncertainty of measurements and their implications for the validity of the final results determines what can be inferred or chosen; begin with the stated conditions and keep the conclusion tied to the evidence.

Example: apply —discuss the uncertainty of measurements and their implications for the validity of the final results to one small, clearly defined case, show the key step or comparison, and explain the result in words.

Boundary: —Discuss the uncertainty of measurements and their implications for the validity of the final results is not a universal recommendation. Check the syllabus scope, assumptions, units and the limits of the evidence before generalising.

CORE PRACTICALS 13a and 13b Carry out redox titrations with both: i iron(II) ions and potassium manganate(VII) ii sodium thiosulfate and iodine.

Use —core practicals 13a and 13b carry out redox titrations with both: i iron(ii) ions and potassium manganate(vii) ii sodium to connect the rule to the data and decision in the question.

This matters because —core practicals 13a and 13b carry out redox titrations with both: i iron(ii) ions and potassium manganate(vii) ii sodium determines what can be inferred or chosen; begin with the stated conditions and keep the conclusion tied to the evidence.

Example: apply —core practicals 13a and 13b carry out redox titrations with both: i iron(ii) ions and potassium manganate(vii) ii sodium to one small, clearly defined case, show the key step or comparison, and explain the result in words.

Boundary: —CORE PRACTICALS 13a and 13b Carry out redox titrations with both: i iron(II) ions and potassium manganate(VII) ii sodium is not a universal recommendation. Check the syllabus scope, assumptions, units and the limits of the evidence before generalising.

Understand that fuel cells use the energy released on the reaction of a fuel with oxygen to generate a voltage Knowledge that methanol and other hydrogen-rich fuels are used in fuel cells is expected.

Use —fuel cells use the energy released on the reaction of a fuel with oxygen to generate a voltage knowledge that methanol to connect the rule to the data and decision in the question.

This matters because —fuel cells use the energy released on the reaction of a fuel with oxygen to generate a voltage knowledge that methanol determines what can be inferred or chosen; begin with the stated conditions and keep the conclusion tied to the evidence.

Example: apply —fuel cells use the energy released on the reaction of a fuel with oxygen to generate a voltage knowledge that methanol to one small, clearly defined case, show the key step or comparison, and explain the result in words.

Boundary: —Fuel cells use the energy released on the reaction of a fuel with oxygen to generate a voltage Knowledge that methanol is not a universal recommendation. Check the syllabus scope, assumptions, units and the limits of the evidence before generalising.

Know the electrode reactions that occur in a hydrogen-oxygen fuel cell Knowledge of hydrogen-oxygen fuel cells with both acidic and alkaline electrolyte is expected.

Use —the electrode reactions that occur in a hydrogen-oxygen fuel cell knowledge of hydrogen-oxygen fuel cells with both acidic to connect the rule to the data and decision in the question.

This matters because —the electrode reactions that occur in a hydrogen-oxygen fuel cell knowledge of hydrogen-oxygen fuel cells with both acidic determines what can be inferred or chosen; begin with the stated conditions and keep the conclusion tied to the evidence.

Example: apply —the electrode reactions that occur in a hydrogen-oxygen fuel cell knowledge of hydrogen-oxygen fuel cells with both acidic to one small, clearly defined case, show the key step or comparison, and explain the result in words.

Boundary: —The electrode reactions that occur in a hydrogen-oxygen fuel cell Knowledge of hydrogen-oxygen fuel cells with both acidic is not a universal recommendation. Check the syllabus scope, assumptions, units and the limits of the evidence before generalising.