Question

Carbon dioxide is used in recarbonation process. A solution has 1 mole/L supersaturated calcium carbonate. Estimated amount of carbon dioxide (in grams) needed to completely convert calcium carbonate to calcium ions in 1 litre solution is __________.

• A. 44.000 gram
• B. 0.044 gram
• C. 40.000 gram
• D. 0.040 gram

Hint:

Always check the mole ratio in the chemical reaction. In recarbonation, CaCO\(_3\) reacts with CO\(_2\) in a 1:1 molar ratio.

Answer 1

The Correct Option is A

The reaction involved in converting calcium carbonate to calcium ions using carbon dioxide is:
\[ \text{CaCO}_3 + \text{CO}_2 + \text{H}_2\text{O} \rightarrow \text{Ca}^{2+} + 2\text{HCO}_3^{-} \]
From the reaction, 1 mole of CaCO\(_3\) requires exactly 1 mole of CO\(_2\).
Given:
1 mole/L of CaCO\(_3\) in 1 L solution \(\Rightarrow\) 1 mole of CaCO\(_3\).
Thus, required CO\(_2\) = 1 mole.
Molecular weight of CO\(_2\) = 44 g/mole.
Hence, amount of CO\(_2\) needed = \(1 \times 44 = 44\) grams.
Final Answer: 44 grams