Question

Assertion (A) – Calcium Carbonate when heated gives Calcium oxide and Water.

Reason (R) – On heating ${\mathrm{CaCO}}_3$, a decomposition reaction takes place.

• A. Both A and R are true, and R is the correct explanation for A.
• B. Both A and R are true, and R is not the correct explanation for A.
• C. A is true but R is false.
• D. A is false but R is true.

Answer 1

The correct option is D

A is false but R is true.

Explanation for correct option:

Assertion:-

• Calcium carbonate when heated it produces Calcium oxide, Carbon dioxide as its products.
• The complete reaction is:

$\underset{\mathrm{Calcium}\mathrm{carbonate}}{{\mathrm{CaCO}}_3\left(\mathrm{s}\right)}\stackrel{∆}{\to }\underset{\mathrm{Calcium}\mathrm{oxide}}{\mathrm{CaO}\left(\mathrm{s}\right)}+\underset{\mathrm{Carbon}\mathrm{dioxide}}{{\mathrm{CO}}_2\left(\mathrm{g}\right)}$

• Thus the assertion is false as Calcium oxide and Carbon dioxide is formed not water when Calcium carbonate is heated.

Explanation for reason:-

• Decomposition reaction is a type of reaction where a compound(reactant) breaks down into two or more compounds(products).
• The heating of Calcium carbonate to from Calcium oxide and Carbon dioxide is an example of a Decomposition reaction.
• The complete reaction is:

$\underset{\mathrm{Calcium}\mathrm{carbonate}}{{\mathrm{CaCO}}_3\left(\mathrm{s}\right)}\stackrel{∆}{\to }\underset{\mathrm{Calcium}\mathrm{oxide}}{\mathrm{CaO}\left(\mathrm{s}\right)}+\underset{\mathrm{Carbon}\mathrm{dioxide}}{{\mathrm{CO}}_2\left(\mathrm{g}\right)}$

Therefore, option (D) A is false but R is true is the correct answer.