What are the products formed in sequence when excess of $\mathrm{CO}_{2}$ is passed in slaked lime?

(C) $\mathrm{CaCO}_{3}, \mathrm{Ca}\left(\mathrm{HCO}_{3}\right)_{2}$

(A) $\mathrm{Ca}\left(\mathrm{HCO}_{3}\right)_{2}, \mathrm{CaCO}_{3}$

(B) $\mathrm{CaO}, \mathrm{CaCO}_{3}$

(D) $\mathrm{CaO}, \mathrm{Ca}\left(\mathrm{HCO}_{3}\right)_{2}$

JEE Main · 2021 · 26 Aug 2021 · Shift 1 · s-Block Elements

What are the products formed in sequence when excess of

CO_{2}

is passed in slaked lime?

Answer: (C)

Carbon dioxide passed into slaked lime first precipitates the sparingly soluble carbonate, which is the milkiness seen in the lime water test:

Ca (OH)_{2} + C O_{2} \to CaC O_{3} ↓ + H_{2} O

Passing more carbon dioxide dissolves that precipitate as the soluble hydrogencarbonate:

CaC O_{3} + C O_{2} + H_{2} O \to Ca (HC O_{3})_{2}

The products formed in sequence are

CaC O_{3}

first and

Ca (HC O_{3})_{2}

afterwards.

JEE Main · 2021 · 26 Aug 2021 · Shift 1 · Single correct option