Temporary And Permanent Hardness And Methods Of Softening Hard Water Jamb Chemistry Past Questions
Question 1
Temporary hard water is formed when rain water containing dissolved carbon(IV) oxide flows over deposits of
- A. CaCO3
- B. Na2CO3
- C. Na2SO4
- D. CaSO4
Question 2
A sample of hard water contains some calcium sulphate and calcium hydrogen carbonate. The total hardness may therefore be removed by
- A. boiling the water
- B. adding excess calcium hydroxide
- C. adding a calculated amount of calcium hydroxide
- D. adding sodium carbonate
Question 3
The two ions responsible for hardness in water are
- A. Ca\(^{2+}\) and / or Mg\(^{2+}\)
- B. K\(^+\) and / or Mg\(^{2+}\)
- C. Ca\(^{2+}\) and / or Li\(^+\)
- D. Ca\(^{2+}\) and / or Na\(^+\)
Question 4
Hard water is water with high concentrations of dissolved ions, in particular calcium and
- A. magnesium ions
- B. nitrogen ions
- C. phosporus ions
- D. helium ions
Question 5
The metal that will react with water only in the form of steam to librate hydrogen gas is?
- A. calcium
- B. aluminium
- C. iron
- D. zinc
