When carbondioxide is bubbled into limewater a white precipitate is formed. If the passage of the gas is continued, the precipitate disappears. The reason for this is
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Correct Answer: Option C
Explanation:
The correct answer is C. Calcium carbonate is formed which on reaction with further carbon dioxide forms soluble calcium hydrogen carbonate.
- When carbon dioxide (CO₂) is bubbled into limewater (which contains calcium hydroxide, Ca(OH)₂), calcium carbonate (CaCO₃) is initially formed as a white precipitate:
\[
\text{Ca(OH)}_2(aq) + \text{CO}_2(g) \rightarrow \text{CaCO}_3(s) + \text{H}_2\text{O}(l)
\]
- If the passage of CO₂ continues, the calcium carbonate dissolves due to the formation of calcium hydrogen carbonate (Ca(HCO₃)₂), which is soluble in water:
\[
\text{CaCO}_3(s) + \text{CO}_2(g) + \text{H}_2\text{O}(l) \rightarrow \text{Ca(HCO₃)}_2(aq)
\]
This is why the precipitate disappears upon continued bubbling of COâ‚‚. Hence, C is the correct explanation.
The correct answer is C. Calcium carbonate is formed which on reaction with further carbon dioxide forms soluble calcium hydrogen carbonate.
- When carbon dioxide (CO₂) is bubbled into limewater (which contains calcium hydroxide, Ca(OH)₂), calcium carbonate (CaCO₃) is initially formed as a white precipitate:
\[
\text{Ca(OH)}_2(aq) + \text{CO}_2(g) \rightarrow \text{CaCO}_3(s) + \text{H}_2\text{O}(l)
\]
- If the passage of CO₂ continues, the calcium carbonate dissolves due to the formation of calcium hydrogen carbonate (Ca(HCO₃)₂), which is soluble in water:
\[
\text{CaCO}_3(s) + \text{CO}_2(g) + \text{H}_2\text{O}(l) \rightarrow \text{Ca(HCO₃)}_2(aq)
\]
This is why the precipitate disappears upon continued bubbling of COâ‚‚. Hence, C is the correct explanation.