A-Level Chemistry Edexcel 9CH0

understand reasons for the trend in ionisation energy down Group 2

understand reasons for the trend in reactivity of Group 7 elements down the group

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, followed by the addition of an organic solvent

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 chlorinein water treatment iii) the disproportionation reaction of chlorine with cold, dilute aqueous sodiumhydroxide to form bleach iv) the disproportionation reaction of chlorine with hot alkali v) reactions analogous to those specified above

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, followed by aqueous ammonia solution iii) hydrogen halides with ammonia and with water (to produce acids)

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

know reactions, including ionic equations where appropriate, for identifying:

i) carbonate ions, CO₃^2–, and hydrogencarbonate ions, HCO₃^–, using an aqueous acid to form carbon dioxide ii) sulfate ions, SO₄^2–, using acidified barium chloride solution iii) ammonium ions, NH₄⁺, using sodium hydroxide solution and warming to form ammonia

Tests for halide ions and for the ions of Group 1 and 2 metals are also required, but are covered elsewhere in this Topic.

understand reasons for the trend in reactivity of the Group 2 elements down the group

know the reactions of the elements Mg to Ba in Group 2 with oxygen, chlorine and water

know the reactions of the oxides of Group 2 elements with water and dilute acid, and their hydroxides with dilute acid

know the trends in solubility of the hydroxides and sulfates of Group 2 elements

understand 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

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 Groups 1 and 2 compounds. *

understand experimental procedures to show:

i) patterns in thermal decomposition of Group 1 and 2 nitrates and carbonates ii) flame colours in compounds of Group 1 and 2 elements

understand reasons for the trends in melting and boiling temperatures, physical state at room temperature, and electronegativity for Group 7 elements