perform calculations including use of the mole concept, involving: (a) reacting masses (from formulas and equations) including percentage yield calculations (b) volumes of gases (e.g. in the burning of hydrocarbons) (c) volumes and concentrations of solutions (d) limiting reagent and excess reagent (When performing calculations, candidates’ answers should reflect the number of significant figures given or asked for in the question. When rounding up or down, candidates should ensure that significant figures are neither lost unnecessarily nor used beyond what is justified (see also Mathematical requirements section)) (e) deduce stoichiometric relationships from calculations such as those in 2.4.1(a)–(d)

recall the reactions (reagents and conditions) by which aldehydes and ketones can be produced: (a) the oxidation of primary alcohols using acidified \( K_2Cr_2O_7 \) or acidified \( KMnO_4 \) and distillation to produce aldehydes (b) the oxidation of secondary alcohols using acidified \( K_2Cr_2O_7 \) or acidified \( KMnO_4 \) and distillation to produce ketones

describe the following reactions of alkenes: (a) the electrophilic addition of (i) hydrogen in a hydrogenation reaction, \( H_2(g) \) and Pt/Ni catalyst and heat (ii) steam, \( H_2O(g) \) and \( H_3PO_4 \) catalyst (iii) a hydrogen halide, \( HX(g) \), at room temperature (iv) a halogen, \( X_2 \) (b) the oxidation by cold dilute acidified \( KMnO_4 \) to form the diol (c) the oxidation by hot concentrated acidified \( KMnO_4 \) leading to the rupture of the carbon–carbon double bond and the identities of the subsequent products to determine the position of alkene linkages in larger molecules (d) addition polymerisation exemplified by the reactions of ethene and propene