Which one of the following does not represent the salt, Calcium carbonate ?
[amp_mcq option1=”Lime water” option2=”Limestone” option3=”Chalk” option4=”Marble” correct=”option1″]
This question was previously asked in
UPSC NDA-2 – 2019
Lime water, however, is a saturated solution of calcium hydroxide ($\text{Ca(OH)}_2$). It is produced by dissolving calcium oxide (quicklime) in water to form calcium hydroxide (slaked lime), and then dissolving the calcium hydroxide in more water. While calcium carbonate can be *formed* by passing carbon dioxide through lime water (causing precipitation), lime water itself is calcium hydroxide solution, not calcium carbonate.
– Lime water is a solution of calcium hydroxide ($\text{Ca(OH)}_2$).
– Passing $\text{CO}_2$ through lime water produces $\text{CaCO}_3$ precipitate.