why lime water and not potassium hydroxide is used to test for carbon (iv) oxide
Lime water is used to test for carbon (IV) oxide because it reacts with carbon dioxide to form calcium carbonate, which is a white precipitate. This reaction is easily visible and indicates the presence of carbon dioxide.
Potassium hydroxide, on the other hand, does not react with carbon dioxide to produce a visible precipitate. It simply dissolves and forms a colorless solution. Therefore, potassium hydroxide is not suitable for testing the presence of carbon (IV) oxide.