I believe lime will neutralize the acidity of things
It is used for the presence of CO2 If the gas is CO2 A precipitate of CaCO3 will form. That is why you require a clear saturated solution.to begin the test.
its so that when you get thirsty you wont have to worry about drinking the same tastless crappy water
Lime water is the common name for saturated calcium hydroxide solution. It is sparsely soluble. Its chemical formula is Ca(OH)2. Since calcium hydroxide is only sparsely soluble, i.e. ca. 1.5 g per liter at 25 °C,[1] there is no visible distinction to clear water. Attentive observers will notice a slightly earthy smell. It is clearly distinguishable by the alkaline taste of the calcium hydroxide. The term lime refers to the mineral, rather than the fruit. When exposed with carbon dioxide, lime water turns into a milky solution.