Here's why:
* Limewater is basic: Limewater is a solution of calcium hydroxide, a strong base, which makes it highly alkaline with a pH greater than 7.
* CO2 is acidic: Carbon dioxide dissolves in water to form carbonic acid (H2CO3), a weak acid.
* Neutralization: When CO2 is bubbled through limewater, the acidic carbonic acid reacts with the basic calcium hydroxide, neutralizing the solution.
* Formation of Calcium Carbonate: This neutralization reaction produces calcium carbonate (CaCO3), which is insoluble in water and forms a white precipitate.
* pH Change: The pH of the solution decreases as the carbonic acid neutralizes the calcium hydroxide, moving it closer to a neutral pH of 7.
Therefore, the resulting product (calcium carbonate) itself doesn't have a pH range. However, the solution's pH decreases as the reaction proceeds, moving from the highly alkaline range of limewater towards a more neutral pH.
Important Note: The exact pH range of the resulting solution would depend on the initial concentration of limewater and the amount of CO2 added.
