The discussion centers on the limewater test, which is commonly used to detect carbon dioxide. Both carbon dioxide and sulphur dioxide can turn limewater milky, leading to confusion about the specificity of the test. While it is noted that prolonged exposure to sulphur dioxide can eventually lead to a clear solution due to the formation of calcium sulfide, this does not make it a reliable test for sulphur dioxide. Additionally, an excess of carbon dioxide can also result in a clear solution through the formation of calcium hydrogencarbonate, complicating the interpretation of results. The conversation highlights the misconception that the limewater test is exclusively indicative of carbon dioxide, as both gases can yield similar outcomes under certain conditions. However, there is a correction regarding the formation of calcium bicarbonate, asserting that it does not occur as a solid.
