Question

5. Calcium oxide reacts vigorously with water to produce slaked lime.
CaO(s) +HO1) + Ca(OH)2(aq)
This reaction can be classified as :
(A) Combination reaction
(B) Exothermic reaction
(C) Endothermic reaction
(D) Oxidation reaction
Which of the following is a correct option ?
(a) (A) and (C)
(b) (C) and (D)
(c) (A), (C) and (D)
(d) (A) and (B)​

Answer 1

Answer:

Explanation:

Quick lime(CaO) combines with water to form calcium hydroxide(Ca(OH)  2

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). It is an exothermic reaction as heat is produced in the reaction.

CaO+H  2

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O→Ca(OH)  2  +heat

On adding excess of calcium hydroxide in water, a saturated solution of calcium hydroxide is formed which is called lime water. Lime water is basic in nature and therefore has a pH above 7.

Answer 2

Answer:

d) A and B

Explanation:

Calcium oxide reacts vigorously with water to produce slaked lime , it is an exothermic process because heat is released and it is an example of combination reaction.

Ca (s) + 2H2O (l) => Ca(OH)² (aq) + H2 (g)