passwella.
Menu

JAMB Chemistry 1987 Question 17

Question 17

Alkanols

Which is the correct set of results for tests conducted respectively on fresh lime juice and ethanol?

  1. A.Add crystals of NaHCO3: fresh lime juice, gas evolved; ethanol, no gas evolved
  2. B.Test with methyl orange: fresh lime juice, turns colourless; ethanol, no change
  3. C.Taste: fresh lime juice, bitter; ethanol, sour
  4. D.Add a piece of sodium: fresh lime juice, no gas evolved; ethanol, hydrogen evolved
Show the answer and explanation

Answer: A (Add crystals of NaHCO3: fresh lime juice, gas evolved; ethanol, no gas evolved)

Explanation

Lime juice contains citric acid, which reacts with hydrogencarbonate to give carbon (IV) oxide; ethanol is not acidic enough to do this. Methyl orange turns red (not colourless) in acid, lime juice is sour, and sodium gives hydrogen with both liquids.