Question

13. Assertion (A): When carbon dioxide gas is passed through lime water, lime water is turned milky.

Reason (R): Calcium carbonate is soluble in water.

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

Answer 1

The correct option is C

(A) is correct but (R) is false.

Explanation for Assertion statement:

• When Carbon dioxide $\left({\mathrm{CO}}_2\right)$ is passed through Lime water or Calcium hydroxide $\left[\mathrm{Ca}{\left(\mathrm{OH}\right)}_2\right]$, it turns milky and Calcium carbonate $\left({\mathrm{CaCO}}_3\right)$ is formed.
• The reaction involved is: $\underset{\mathrm{Lime}\mathrm{water}}{\mathrm{Ca}{\left(\mathrm{OH}\right)}_2}+\underset{\mathrm{Carbon}\mathrm{dioxide}}{{\mathrm{CO}}_2}\to \underset{\mathrm{Calcium}\mathrm{carbonate}\left(\mathrm{milkiness}\right)}{{\mathrm{CaCO}}_3}+\underset{\mathrm{Water}}{{\mathrm{H}}_2\mathrm{O}}$

Explanation for Reason statement:

• Calcium carbonate formed is insoluble in water because there is a strong electrostatic force of attraction between the ions of Calcium carbonate.

Hence, option (C) is the correct answer. (A) is correct but (R) is false.