Topic 8: Redox Chemistry and Groups 1, 2 and 7

Know what is meant by the term ‘oxidation number’ and understand the rules for assigning oxidation numbers.

Use —what is meant by the term ‘oxidation number’ and understand the rules for assigning oxidation numbers to connect the rule to the data and decision in the question.

This matters because —what is meant by the term ‘oxidation number’ and understand the rules for assigning oxidation numbers 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 ‘oxidation number’ and understand the rules for assigning oxidation numbers 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 ‘oxidation number’ and understand the rules for assigning oxidation numbers is not a universal recommendation. Check the syllabus scope, assumptions, units and the limits of the evidence before generalising.

Be able to calculate the oxidation number of elements in compounds and ions, including in peroxides and metal hydrides.

Use —the oxidation number of elements in compounds and ions to connect the rule to the data and decision in the question.

This matters because —the oxidation number of elements in compounds and ions determines what can be inferred or chosen; begin with the stated conditions and keep the conclusion tied to the evidence.

Example: apply —the oxidation number of elements in compounds and ions to one small, clearly defined case, show the key step or comparison, and explain the result in words.

Boundary: —The oxidation number of elements in compounds and ions is not a universal recommendation. Check the syllabus scope, assumptions, units and the limits of the evidence before generalising.

Be able to indicate the oxidation number of an element in a compound or an ion, using a Roman numeral.

Use —indicate the oxidation number of an element in a compound or an ion to connect the rule to the data and decision in the question.

This matters because —indicate the oxidation number of an element in a compound or an ion determines what can be inferred or chosen; begin with the stated conditions and keep the conclusion tied to the evidence.

Example: apply —indicate the oxidation number of an element in a compound or an ion to one small, clearly defined case, show the key step or comparison, and explain the result in words.

Boundary: —Indicate the oxidation number of an element in a compound or an ion is not a universal recommendation. Check the syllabus scope, assumptions, units and the limits of the evidence before generalising.

Be able to write formulae given oxidation numbers.

Use —write formulae given oxidation numbers to connect the rule to the data and decision in the question.

This matters because —write formulae given oxidation numbers determines what can be inferred or chosen; begin with the stated conditions and keep the conclusion tied to the evidence.

Example: apply —write formulae given oxidation numbers to one small, clearly defined case, show the key step or comparison, and explain the result in words.

Boundary: use the formula and units given in the question, show the substitution and interpret the result; the calculation alone is not the conclusion.

Understand oxidation and reduction in terms of electron transfer and changes in oxidation number, and the application of these ideas to reactions of s-block and p-block elements.

Use —oxidation and reduction in terms of electron transfer and changes in oxidation number, and the application of these ideas to connect the rule to the data and decision in the question.

This matters because —oxidation and reduction in terms of electron transfer and changes in oxidation number, and the application of these ideas determines what can be inferred or chosen; begin with the stated conditions and keep the conclusion tied to the evidence.

Example: apply —oxidation and reduction in terms of electron transfer and changes in oxidation number, and the application of these ideas to one small, clearly defined case, show the key step or comparison, and explain the result in words.

Boundary: —Oxidation and reduction in terms of electron transfer and changes in oxidation number, and the application of these ideas is not a universal recommendation. Check the syllabus scope, assumptions, units and the limits of the evidence before generalising.

Know that oxidising agents gain electrons and reducing agents lose electrons.

Use —oxidising agents gain electrons and reducing agents lose electrons to connect the rule to the data and decision in the question.

This matters because —oxidising agents gain electrons and reducing agents lose electrons determines what can be inferred or chosen; begin with the stated conditions and keep the conclusion tied to the evidence.

Example: apply —oxidising agents gain electrons and reducing agents lose electrons to one small, clearly defined case, show the key step or comparison, and explain the result in words.

Boundary: —Oxidising agents gain electrons and reducing agents lose electrons is not a universal recommendation. Check the syllabus scope, assumptions, units and the limits of the evidence before generalising.

Understand that a disproportionation reaction involves an element in a single species being simultaneously oxidised and reduced.

Use —a disproportionation reaction involves an element in a single species being simultaneously oxidised and reduced to connect the rule to the data and decision in the question.

This matters because —a disproportionation reaction involves an element in a single species being simultaneously oxidised and reduced determines what can be inferred or chosen; begin with the stated conditions and keep the conclusion tied to the evidence.

Example: apply —a disproportionation reaction involves an element in a single species being simultaneously oxidised and reduced to one small, clearly defined case, show the key step or comparison, and explain the result in words.

Boundary: —A disproportionation reaction involves an element in a single species being simultaneously oxidised and reduced is not a universal recommendation. Check the syllabus scope, assumptions, units and the limits of the evidence before generalising.

Know that oxidation number is a useful concept in terms of the classification of reactions as redox and as disproportionation.

Use —oxidation number is a useful concept in terms of the classification of reactions as redox and as disproportionation to connect the rule to the data and decision in the question.

This matters because —oxidation number is a useful concept in terms of the classification of reactions as redox and as disproportionation determines what can be inferred or chosen; begin with the stated conditions and keep the conclusion tied to the evidence.

Example: apply —oxidation number is a useful concept in terms of the classification of reactions as redox and as disproportionation to one small, clearly defined case, show the key step or comparison, and explain the result in words.

Boundary: —Oxidation number is a useful concept in terms of the classification of reactions as redox and as disproportionation is not a universal recommendation. Check the syllabus scope, assumptions, units and the limits of the evidence before generalising.

Understand that metals, in general, form positive ions by loss of electrons with an increase in oxidation number whereas non-metals, in general, form negative ions by gain of electrons with a decrease in oxidation number.

Use —metals, in general, form positive ions by loss of electrons with an increase in oxidation number whereas non-metals to connect the rule to the data and decision in the question.

This matters because —metals, in general, form positive ions by loss of electrons with an increase in oxidation number whereas non-metals determines what can be inferred or chosen; begin with the stated conditions and keep the conclusion tied to the evidence.

Example: apply —metals, in general, form positive ions by loss of electrons with an increase in oxidation number whereas non-metals to one small, clearly defined case, show the key step or comparison, and explain the result in words.

Boundary: —Metals, in general, form positive ions by loss of electrons with an increase in oxidation number whereas non-metals is not a universal recommendation. Check the syllabus scope, assumptions, units and the limits of the evidence before generalising.

Be able to write ionic half-equations and use them to construct full ionic equations 8B: The elements of Groups 1 and 2 Students will be assessed on their ability to:.

Use —write ionic half-equations and use them to construct full ionic equations 8b: the elements of groups 1 and 2 students will to connect the rule to the data and decision in the question.

This matters because —write ionic half-equations and use them to construct full ionic equations 8b: the elements of groups 1 and 2 students will determines what can be inferred or chosen; begin with the stated conditions and keep the conclusion tied to the evidence.

Example: apply —write ionic half-equations and use them to construct full ionic equations 8b: the elements of groups 1 and 2 students will to one small, clearly defined case, show the key step or comparison, and explain the result in words.

Boundary: use the formula and units given in the question, show the substitution and interpret the result; the calculation alone is not the conclusion.

Understand reasons for the trend in ionisation energy down Groups 1 and 2.

Use —reasons for the trend in ionisation energy down groups 1 and 2 to connect the rule to the data and decision in the question.

This matters because —reasons for the trend in ionisation energy down groups 1 and 2 determines what can be inferred or chosen; begin with the stated conditions and keep the conclusion tied to the evidence.

Example: apply —reasons for the trend in ionisation energy down groups 1 and 2 to one small, clearly defined case, show the key step or comparison, and explain the result in words.

Boundary: —Reasons for the trend in ionisation energy down Groups 1 and 2 is not a universal recommendation. Check the syllabus scope, assumptions, units and the limits of the evidence before generalising.

Understand reasons for the trend in reactivity of the elements down Group 1 (Li to K) and Group 2 (Mg to Ba).

Use —reasons for the trend in reactivity of the elements down group 1 (li to k) and group 2 (mg to ba) to connect the rule to the data and decision in the question.

This matters because —reasons for the trend in reactivity of the elements down group 1 (li to k) and group 2 (mg to ba) determines what can be inferred or chosen; begin with the stated conditions and keep the conclusion tied to the evidence.

Example: apply —reasons for the trend in reactivity of the elements down group 1 (li to k) and group 2 (mg to ba) to one small, clearly defined case, show the key step or comparison, and explain the result in words.

Boundary: —Reasons for the trend in reactivity of the elements down Group 1 (Li to K) and Group 2 (Mg to Ba) is not a universal recommendation. Check the syllabus scope, assumptions, units and the limits of the evidence before generalising.

Know the reactions of the elements of Group 1 (Li to K) and Group 2 (Mg to Ba) with oxygen, chlorine and water.

Use —the reactions of the elements of group 1 (li to k) and group 2 (mg to ba) with oxygen, chlorine and water to connect the rule to the data and decision in the question.

This matters because —the reactions of the elements of group 1 (li to k) and group 2 (mg to ba) with oxygen, chlorine and water determines what can be inferred or chosen; begin with the stated conditions and keep the conclusion tied to the evidence.

Example: apply —the reactions of the elements of group 1 (li to k) and group 2 (mg to ba) with oxygen, chlorine and water to one small, clearly defined case, show the key step or comparison, and explain the result in words.

Boundary: —The reactions of the elements of Group 1 (Li to K) and Group 2 (Mg to Ba) with oxygen, chlorine and water is not a universal recommendation. Check the syllabus scope, assumptions, units and the limits of the evidence before generalising.

Know the reactions of: i oxides of Group 1 and 2 elements with water and dilute acid ii hydroxides of Group 1 and 2 elements with dilute acid.

Use —the reactions of: i oxides of group 1 and 2 elements with water and dilute acid ii hydroxides of group 1 and 2 elements to connect the rule to the data and decision in the question.

This matters because —the reactions of: i oxides of group 1 and 2 elements with water and dilute acid ii hydroxides of group 1 and 2 elements determines what can be inferred or chosen; begin with the stated conditions and keep the conclusion tied to the evidence.

Example: apply —the reactions of: i oxides of group 1 and 2 elements with water and dilute acid ii hydroxides of group 1 and 2 elements to one small, clearly defined case, show the key step or comparison, and explain the result in words.

Boundary: —The reactions of: i oxides of Group 1 and 2 elements with water and dilute acid ii hydroxides of Group 1 and 2 elements is not a universal recommendation. Check the syllabus scope, assumptions, units and the limits of the evidence before generalising.

Know the trends in solubility of the hydroxides and sulfates of Group 2 elements.

Use —the trends in solubility of the hydroxides and sulfates of group 2 elements to connect the rule to the data and decision in the question.

This matters because —the trends in solubility of the hydroxides and sulfates of group 2 elements determines what can be inferred or chosen; begin with the stated conditions and keep the conclusion tied to the evidence.

Example: apply —the trends in solubility of the hydroxides and sulfates of group 2 elements to one small, clearly defined case, show the key step or comparison, and explain the result in words.

Boundary: —The trends in solubility of the hydroxides and sulfates of Group 2 elements is not a universal recommendation. Check the syllabus scope, assumptions, units and the limits of the evidence before generalising.

Understand the reasons for the trends in thermal stability of the nitrates and the carbonates of the elements in Groups 1 and 2 in terms of the size and charge of the cations involved.

Use —the reasons for the trends in thermal stability of the nitrates and the carbonates of the elements in groups 1 and 2 to connect the rule to the data and decision in the question.

This matters because —the reasons for the trends in thermal stability of the nitrates and the carbonates of the elements in groups 1 and 2 determines what can be inferred or chosen; begin with the stated conditions and keep the conclusion tied to the evidence.

Example: apply —the reasons for the trends in thermal stability of the nitrates and the carbonates of the elements in groups 1 and 2 to one small, clearly defined case, show the key step or comparison, and explain the result in words.

Boundary: —The reasons for the trends in thermal stability of the nitrates and the carbonates of the elements in Groups 1 and 2 is not a universal recommendation. Check the syllabus scope, assumptions, units and the limits of the evidence before generalising.

Understand the formation of characteristic flame colours by Group 1 and 2 compounds in terms of electron transitions Students will be expected to know the flame colours for Group 1 and 2 compounds.

Use —the formation of characteristic flame colours by group 1 and 2 compounds in terms of electron transitions students will be to connect the rule to the data and decision in the question.

This matters because —the formation of characteristic flame colours by group 1 and 2 compounds in terms of electron transitions students will be determines what can be inferred or chosen; begin with the stated conditions and keep the conclusion tied to the evidence.

Example: apply —the formation of characteristic flame colours by group 1 and 2 compounds in terms of electron transitions students will be to one small, clearly defined case, show the key step or comparison, and explain the result in words.

Boundary: —The formation of characteristic flame colours by Group 1 and 2 compounds in terms of electron transitions Students will be is not a universal recommendation. Check the syllabus scope, assumptions, units and the limits of the evidence before generalising.

Know experimental procedures to show: i patterns in the thermal decomposition of Group 1 and 2 nitrates and carbonates Students will be expected to know tests for carbon dioxide and oxygen; and to recognise nitrogen dioxide by its colour and acidic pH. ii flame colours in compounds of Group 1 and 2 elements.

Use —experimental procedures to show: i patterns in the thermal decomposition of group 1 and 2 nitrates and carbonates students to connect the rule to the data and decision in the question.

This matters because —experimental procedures to show: i patterns in the thermal decomposition of group 1 and 2 nitrates and carbonates students determines what can be inferred or chosen; begin with the stated conditions and keep the conclusion tied to the evidence.

Example: apply —experimental procedures to show: i patterns in the thermal decomposition of group 1 and 2 nitrates and carbonates students to one small, clearly defined case, show the key step or comparison, and explain the result in words.

Boundary: —Experimental procedures to show: i patterns in the thermal decomposition of Group 1 and 2 nitrates and carbonates Students is not a universal recommendation. Check the syllabus scope, assumptions, units and the limits of the evidence before generalising.

Know reactions, including ionic equations where appropriate, for identifying: (i) carbonate ions, CO3^2−, and hydrogencarbonate ions, HCO3−, using aqueous acid to form carbon dioxide and limewater to test the gas; (ii) sulfate ions, SO4^2−, using acidified barium chloride solution; and (iii) ammonium ions, NH4+, using sodium hydroxide solution and warming to form ammonia, tested with litmus and HCl fumes.

Use —reactions to connect the rule to the data and decision in the question.

This matters because —reactions determines what can be inferred or chosen; begin with the stated conditions and keep the conclusion tied to the evidence.

Example: apply —reactions to one small, clearly defined case, show the key step or comparison, and explain the result in words.

Boundary: —Reactions is not a universal recommendation. Check the syllabus scope, assumptions, units and the limits of the evidence before generalising.

Be able to calculate solution concentrations, in mol dm-3 and g dm-3, including simple acid-base titrations using the indicators methyl orange and phenolphthalein.

Use —solution concentrations, in mol dm-3 and g dm-3 to connect the rule to the data and decision in the question.

This matters because —solution concentrations, in mol dm-3 and g dm-3 determines what can be inferred or chosen; begin with the stated conditions and keep the conclusion tied to the evidence.

Example: apply —solution concentrations, in mol dm-3 and g dm-3 to one small, clearly defined case, show the key step or comparison, and explain the result in words.

Boundary: —Solution concentrations, in mol dm-3 and g dm-3 is not a universal recommendation. Check the syllabus scope, assumptions, units and the limits of the evidence before generalising.

CORE PRACTICAL 3 Finding the concentration of a solution of hydrochloric acid.

Use —core practical 3 finding the concentration of a solution of hydrochloric acid to connect the rule to the data and decision in the question.

This matters because —core practical 3 finding the concentration of a solution of hydrochloric acid determines what can be inferred or chosen; begin with the stated conditions and keep the conclusion tied to the evidence.

Example: apply —core practical 3 finding the concentration of a solution of hydrochloric acid to one small, clearly defined case, show the key step or comparison, and explain the result in words.

Boundary: —CORE PRACTICAL 3 Finding the concentration of a solution of hydrochloric acid is not a universal recommendation. Check the syllabus scope, assumptions, units and the limits of the evidence before generalising.

Understand how to minimise the sources of measurement uncertainty in volumetric analysis and estimate the overall uncertainty in the calculated result.

Use —how to minimise the sources of measurement uncertainty in volumetric analysis and estimate the overall uncertainty in to connect the rule to the data and decision in the question.

This matters because —how to minimise the sources of measurement uncertainty in volumetric analysis and estimate the overall uncertainty in determines what can be inferred or chosen; begin with the stated conditions and keep the conclusion tied to the evidence.

Example: apply —how to minimise the sources of measurement uncertainty in volumetric analysis and estimate the overall uncertainty in to one small, clearly defined case, show the key step or comparison, and explain the result in words.

Boundary: —How to minimise the sources of measurement uncertainty in volumetric analysis and estimate the overall uncertainty in is not a universal recommendation. Check the syllabus scope, assumptions, units and the limits of the evidence before generalising.

CORE PRACTICAL 4 Preparation of a standard solution from a solid acid and use it to find the concentration of a solution of sodium hydroxide.

Use —core practical 4 preparation of a standard solution from a solid acid and use it to find the concentration of a solution to connect the rule to the data and decision in the question.

This matters because —core practical 4 preparation of a standard solution from a solid acid and use it to find the concentration of a solution determines what can be inferred or chosen; begin with the stated conditions and keep the conclusion tied to the evidence.

Example: apply —core practical 4 preparation of a standard solution from a solid acid and use it to find the concentration of a solution to one small, clearly defined case, show the key step or comparison, and explain the result in words.

Boundary: —CORE PRACTICAL 4 Preparation of a standard solution from a solid acid and use it to find the concentration of a solution is not a universal recommendation. Check the syllabus scope, assumptions, units and the limits of the evidence before generalising.

Understand reasons for the trends for Group 7 elements in: i melting and boiling temperatures and physical state at room temperature ii electronegativity iii reactivity down the group.

Use —reasons for the trends for group 7 elements in: i melting and boiling temperatures and physical state at room temperature ii to connect the rule to the data and decision in the question.

This matters because —reasons for the trends for group 7 elements in: i melting and boiling temperatures and physical state at room temperature ii determines what can be inferred or chosen; begin with the stated conditions and keep the conclusion tied to the evidence.

Example: apply —reasons for the trends for group 7 elements in: i melting and boiling temperatures and physical state at room temperature ii to one small, clearly defined case, show the key step or comparison, and explain the result in words.

Boundary: —Reasons for the trends for Group 7 elements in: i melting and boiling temperatures and physical state at room temperature ii is not a universal recommendation. Check the syllabus scope, assumptions, units and the limits of the evidence before generalising.

Understand the trend in reactivity of Group 7 elements in terms of the redox reactions of Cl2, Br2 and I2 with halide ions in aqueous solution Students are expected to know the colours of the elements in standard conditions, in aqueous solution and in a non-polar organic solvent.

Use —the trend in reactivity of group 7 elements in terms of the redox reactions of cl2, br2 and i2 with halide ions in aqueous to connect the rule to the data and decision in the question.

This matters because —the trend in reactivity of group 7 elements in terms of the redox reactions of cl2, br2 and i2 with halide ions in aqueous determines what can be inferred or chosen; begin with the stated conditions and keep the conclusion tied to the evidence.

Example: apply —the trend in reactivity of group 7 elements in terms of the redox reactions of cl2, br2 and i2 with halide ions in aqueous to one small, clearly defined case, show the key step or comparison, and explain the result in words.

Boundary: —The trend in reactivity of Group 7 elements in terms of the redox reactions of Cl2, Br2 and I2 with halide ions in aqueous is not a universal recommendation. Check the syllabus scope, assumptions, units and the limits of the evidence before generalising.

Understand, in terms of changes in oxidation number, the following reactions of the halogens: i oxidation reactions with Group 1 and 2 metals ii the disproportionation reaction of chlorine with water and the use of chlorine in water treatment iii the disproportionation reaction of chlorine with cold, dilute aqueous sodium hydroxide to form bleach iv the disproportionation reaction of chlorine with hot alkali v reactions analogous to those specified above.

Use —understand, in terms of changes in oxidation number, the following reactions of the halogens: i oxidation reactions to connect the rule to the data and decision in the question.

This matters because —understand, in terms of changes in oxidation number, the following reactions of the halogens: i oxidation reactions determines what can be inferred or chosen; begin with the stated conditions and keep the conclusion tied to the evidence.

Example: apply —understand, in terms of changes in oxidation number, the following reactions of the halogens: i oxidation reactions to one small, clearly defined case, show the key step or comparison, and explain the result in words.

Boundary: —Understand, in terms of changes in oxidation number, the following reactions of the halogens: i oxidation reactions is not a universal recommendation. Check the syllabus scope, assumptions, units and the limits of the evidence before generalising.

Understand the following reactions: i solid Group 1 halides with concentrated sulfuric acid, to illustrate the trend in reducing ability of the hydrogen halides ii precipitation reactions of the aqueous anions Cl-, Br- and I- with aqueous silver nitrate solution and nitric acid, and the solubility of the precipitates in aqueous ammonia solution iii hydrogen halides with ammonia gas (to produce ammonium halides) and with water (to produce acids).

Use —the following reactions: i solid group 1 halides with concentrated sulfuric acid, to illustrate the trend in reducing to connect the rule to the data and decision in the question.

This matters because —the following reactions: i solid group 1 halides with concentrated sulfuric acid, to illustrate the trend in reducing determines what can be inferred or chosen; begin with the stated conditions and keep the conclusion tied to the evidence.

Example: apply —the following reactions: i solid group 1 halides with concentrated sulfuric acid, to illustrate the trend in reducing to one small, clearly defined case, show the key step or comparison, and explain the result in words.

Boundary: —The following reactions: i solid Group 1 halides with concentrated sulfuric acid, to illustrate the trend in reducing is not a universal recommendation. Check the syllabus scope, assumptions, units and the limits of the evidence before generalising.

Be able to make predictions about fluorine and astatine and their compounds, in terms of knowledge of trends in halogen chemistry.

Use —make predictions about fluorine and astatine and their compounds, in terms of knowledge of trends in halogen chemistry to connect the rule to the data and decision in the question.

This matters because —make predictions about fluorine and astatine and their compounds, in terms of knowledge of trends in halogen chemistry determines what can be inferred or chosen; begin with the stated conditions and keep the conclusion tied to the evidence.

Example: apply —make predictions about fluorine and astatine and their compounds, in terms of knowledge of trends in halogen chemistry to one small, clearly defined case, show the key step or comparison, and explain the result in words.

Boundary: —Make predictions about fluorine and astatine and their compounds, in terms of knowledge of trends in halogen chemistry is not a universal recommendation. Check the syllabus scope, assumptions, units and the limits of the evidence before generalising.