Question

Is there any other gas than $C{O_2}$ that turns limewater milky?

Answer 1

A dilute aqueous solution of calcium hydroxide is known as lime water. At normal temperature, calcium hydroxide ( $Ca{(OH)_2}$ ) is only slightly soluble in water. Calcium hydroxide can be prepared by mixing calcium hydroxide with water and eliminating any undissolved solutes.

Complete Step By Step Answer:
To detect the presence of $C{O_2}$ , lime water is commonly used. Carbon dioxide combines with lime water to generate calcium carbonate, an insoluble milky substance.
$C{O_2} + Ca{(OH)_2} \to CaC{O_3} + {H_2}O$
Sulphur dioxide reacts with lime water ( $Ca{(OH)_2}$ ) and forms calcium sulphite as a product.
$S{O_2} + Ca{(OH)_2} \to CaS{O_3} + {H_2}O$
The colour of calcium sulfite is milky white.
Due to the production of calcium hydrogen sulphite, the milkiness vanishes. Calcium hydrogen sulphide is water soluble.
$CaS{O_3} + S{O_2} + {H_2}O \to Ca{(HS{O_3})_2}$
Hence, $S{O_2}$ (Sulphur dioxide) turns lime water milky due to the formation of calcium sulfite ( $CaS{O_3}$ ).
Additional Information: Slaked lime ( $Ca{(OH)_2}$ ) is calcium hydroxide ( $Ca{(OH)_2}$ ).
The reaction of water with calcium oxide produces calcium hydroxide.
$CaO + {H_2}O \to Ca{\left( {OH} \right)_2}$
When calcium oxide is combined with water, a small amount of calcium oxide dissolves, resulting in limewater.
We can detect carbon dioxide and sulphur dioxide using lime water.
Carbon dioxide has no odour; however, sulphur dioxide has a strong odour.
Sulphur dioxide changes the colour of potassium dichromate paper to green, whereas carbon dioxide has no effect on the colour of potassium dichromate paper.

Note:
Lime water is known to turn into milk when exposed to carbon dioxide. This occurs as a result of the formation of insoluble calcium carbonate. Calcium sulphide is formed when sulphur dioxide reacts with calcium hydroxide to form a milky precipitate, but it takes longer to form than calcium carbonate.