Question

A compound 'A' is used in the manufacture of cement. When dissolved in
water, it evolves a large amount of heat and forms compound 'B'.
(1) Identify A and B.
(11) Write chemical equation for the reaction of A with water.
(iii) List two types of reaction in which this reaction may be classified.
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Answer 1

The answers to the questions are given below.

Explanation:

• Let's say the compound A = Calcium Oxide "CaO"
• The compound B = calcium Hydroxide "Ca(OH)2
• The chemical reaction for the formation of calcium hydroxide from calcium oxide is given as below.
• CaO + H2O ------>  Ca(OH)2
• When CaO is dissolved in water it releases a large amount of heat energy and is known as an exothermic reaction.
• It is also known as a combination reaction.

Answer 2

Answer:

Explanation:

A =Calcium Oxide

B =Calcium Hydroxide

Cao +H2O. - - - - - - Ca(OH)2

Combination and Exothermic