limewater
(noun)
an aqueous solution of Ca(OH)2; a common indicator used to detect the presence of carbon dioxide gas
Examples of limewater in the following topics:
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Gas Evolution Reactions
- The test tube on the right contains limewater (a solution of calcium hydroxide, Ca(OH)2).
- As the reaction proceeds, the limewater on the right turns from clear to milky; this is due to the $CO_2(g)$ reacting with the aqueous calcium hydroxide to form calcium carbonate, which is only slightly soluble in water.
- When this experiment is repeated with nitric or sulfuric acid instead of HCl, it yields the same results: the clear limewater turns milky, indicating the production of carbon dioxide.
- Carbon dioxide (formed from bicarbonate) and an acid react with limewater, turning it from clear to milky.