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CHEMISTRY

JAMB 2011 - Question 14

Chemistry 2011 JAMB Past Questions - Question 14: Hardness of water is mainly due to the presence of

Choose the correct answers from the options given.

Hardness of water is mainly due to the presence of

A: calcium hydroxide or magnesium hydroxide

B: calcium trioxocarbonate (IV) or calcium tetraoxosulphate (VI)

C: sodium hydroxide or magnesium hydroxide

D: calcium chloride or sodium chloride salts.

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Correct Answer

Explanation

The hardness of water is mainly due to the presence of calcium and magnesium ions, typically in the form of calcium hydroxide (Ca(OH)?) and magnesium hydroxide (Mg(OH)?). These ions are responsible for causing what is known as "hard water." Therefore, the correct answer would be:

- Calcium hydroxide or magnesium hydroxide