Question

Assertion(A) : The reaction of Calcium oxide with water to produce slaked lime releasing a large amount of heat is a combination reaction Reason (R ) :Double displacement reaction are the reaction in which there is exchange of ions between the reactants
choose correct one
(a) Both (A) and (R) are true and (R)is the correct explanation of the assertion.

(b) Both (A) and (R) are true and (R)is not the correct explanation of the assertion.

(c) (A) is true and (R) is false

(d) (A) is false but (R) is true.
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Answer 1

Answer: its B

Explanation:

Both the assertion and reason are true. But, reason is not the explanation of assertion. Calcium Oxide reacts with water to form Calcium Hydroxide which is a Combination Reaction.

Answer 2

The reaction of Calcium oxide with water to produce slaked lime releasing a large amount of heat is a combination reaction. Double displacement reactions are the reaction in which there is an exchange of ions between the reactants. Both assertion and reason are true but the reason is not the correct explanation of the assertion. Thus, the correct option is (b).

Explanation:

• When calcium oxide ($\[CaO\]$) is treated with water, they combine together to form slaked lime ($\[Ca{(OH)_2}\]$) and evolve a large amount of heat energy.
• This reaction is called a combination reaction because, in this reaction, two substances react together to form a new compound.
• The reaction is given as:

        $\[CaO + {H_2}O \to Ca{(OH)_2} + Heat\]$

• A reaction in which an exchange of ions between the reactants takes place to form new compounds is called a double displacement reaction. Example - $\[N{a_2}S{O_4} + BaC{l_2} \to BaS{O_4} + 2NaCl\]$

• Therefore, both the assertion and reason are true but the reason is not the correct explanation of the assertion.