passwella.
Menu

JAMB Chemistry 1984 Question 40

Question 40

Water

Water is said to be 'hard' if it

  1. A.easily forms ice
  2. B.has to be warmed before sodium chloride dissolves in it
  3. C.forms an insoluble scum with soap
  4. D.contains nitrates
  5. E.contains sodium ions
Show the answer and explanation

Answer: C (forms an insoluble scum with soap)

Explanation

Hard water contains dissolved calcium and magnesium ions, which react with soap to form an insoluble scum instead of a lather.