Solid calcium oxide reacts vigorously with water to form calcium hydroxide accompanied by the liberation of heat. This process is called slaking of lime. Calcium hydroxide dissolves in water to form its solution called lime water. Which among the following is (are) true about slaking of lime and the solution formed?
  1. It is an endothermic reaction
  2. It is an exothermic reaction
  3. The pH of the resulting solution will be more than seven
  4. The pH of the resulting solution will be less than seven
(a) (i) and (ii)
(b) (ii) and (iii)
(c) (i) and (iv)
(d) (iii) and (iv)

AcademicChemistryNCERTClass 10

Correct Answer:  (b) (ii) and (iii)

Explanation: When solid calcium oxide reacts vigorously with water, it forms calcium hydroxide which is accompanied by the generation of heat (exothermic reaction). The pH of the solution will be more than 7 because oxides and hydroxides of metals are alkaline.

raja
Updated on 10-Oct-2022 13:27:08

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