Which one of the following processes will produce hard water?
Correct answer: B. Saturation of water with CaSO4
- A. Saturation of water with MgCO3
- B. Saturation of water with CaSO4
- C. Addition of Na2SO4 to water
- D. Saturation of water with CaCO3
Explanation
Hardness in water is caused by the presence of dissolved calcium (Ca²⁺) and magnesium (Mg²⁺) ions. Calcium sulfate (CaSO₄) is a salt that dissolves in water to produce Ca²⁺ ions, thus contributing to permanent hardness.
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About s-Block and p-Block Elements
The s and p blocks are studied through their valence-shell configurations, periodic trends and characteristic chemical properties. Work covers the reactions of Group I and Group II elements, the behaviour of Group IV elements, and how atomic size, ionization energy, electronegativity and metallic character change across periods and down groups.
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