(a)(i) What is the general formula for alkanoic acids? (ii) State two chemical properties of ethanoic acid. (b) Which of propene, butane and pentane (i) will decolorize acidified KMnO solution? (ii) can be easily polymerized? (iii) is an isomer of methylpropane? (iv) can be obtained from an alkanol by dehydration?
Explanation
(i) General formula for alkanoic acid is CH COOH. Two chemical properties of ethanoic acid - Reacts with alkanols to form ethanoates or alkanoates or esters (esterification) - Reacts with trioxocarbonate (IV) or hydrogen trioxocarbonate (IV) to produce carbon (IV) oxide - Reacts with sodium hydroxide or potassium hydroxide to form sodium or potassium ethanoate.
(b)(i) Propene will decolorize acidified KMnO solution (ii) Propene can easily be polymerised (iii) Butane is an isomer of methylpropane (iv) Propene can be obtained from alkanol by dehydration.
