5 Turn over 2 This question is about alcohols and their reactions. The table gives some of the names and skeletal formulae of isomers having the formula C4H9OH. (a) Complete the table. (2) Name Skeletal formula OH butan‑2‑ol OH 2‑methylpropan‑1‑ol 2‑methylpropan‑2‑ol OH 6 (b) (i) Some alcohols react with concentrated phosphoric acid to form alkenes. What is the type of this reaction? (1) A addition B elimination C oxidation D substitution (ii) When butan‑2‑ol reacts with concentrated phosphoric acid, two stereoisomers are formed. Explain what is meant by the term stereoisomers. (2) .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... (iii) Draw the structures and give the names of the two stereoisomers. (2) Stereoisomer 1 Stereoisomer 2 Name: Name: (iv) Name this type of stereoisomerism. (1) .................................................................................................................................................................................................................................................................................... 7 Turn over (c) 2‑methylpropan‑2‑ol may be formed by the reaction between 2‑bromo‑2‑methylpropane and aqueous potassium hydroxide. What is the role of the hydroxide ions in this reaction? (1) A alkali B catalyst C electrophile D nucleophile (d) (i) CH3CH2CH2CH2OH reacts with the oxidising agent potassium dichromate(VI) in dilute sulfuric acid. Two organic products can be formed, depending on the conditions. Write a balanced equation for the formation of one of these products, giving its name and the condition required to achieve this product in high yield. Use [O] in the equation to represent each oxygen atom from the oxidising agent. (3) Equation Name .................................................................................................................................................................................................................................................................... Condition . ........................................................................................................................................................................................................................................................ (ii) The colour of the solution at the end of the reaction in (d)(i) will be (1) A brown B green C orange D yellow (Total for Question 2 = 13 marks)