(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\(_4\) 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 C\(_n\)H\(_{2n + 1}\) 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\(_4\) solution (ii) Propene can easily be polymerised (iii) Butane is an isomer of methylpropane (iv) Propene can be obtained from alkanol by dehydration.
