Question

Solid calcium oxide reacts vigorously with water to form calcium hydroxide accompanied by liberation of heat. This process is called slaking of lime. Calcium hydroxide dissolves in water to form a 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

विकल्प

•  (i) and (ii)

• (ii) and (iii)

• (i) and (iv)

• (iii) and (iv).

Answer 1

(ii) and (iii)

Explanation - 

Slaking of lime is an exothermic process. Lime (CaO) dissolves in water to form calcium hydroxide called slaked lime Ca(OH)₂. Since it is a base, the pH of solution will become more than seven (7).