Older MCQs might not have the typical A, B, C,
D
choices. They
have choices 1, 2, 3, and a combination of them is the answer. Below is the key that maps such
combinations to the answer.
A
1, 2 and 3 are correct
B
1 and 2 only are correct
C
2 and 3 only are correct
D
1 only is correct
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
recall the reactions (reagents and conditions) by which alcohols can be produced: (a) electrophilic addition of steam to an alkene, \( H_2O(g) \) and \( H_3PO_4 \) catalyst (b) reaction of alkenes with cold dilute acidified potassium manganate(VII) to form a diol (c) substitution of a halogenoalkane using NaOH(aq) and heat (d) reduction of an aldehyde or ketone using NaB\(_4\) or LiAl\(_4\) (e) reduction of a carboxylic acid using LiAl\(_4\) (f) hydrolysis of an ester using dilute acid or dilute alkali and heat
