Calcium hydroxide (Ca(OH)2) is a chemical compound commonly known as slaked lime or hydrated lime. It is a white, crystalline solid that is sparingly soluble in water. On the other hand, carbon dioxide (CO2) is a colorless gas that is naturally present in the atmosphere.

When calcium hydroxide reacts with carbon dioxide, a chemical reaction occurs, resulting in the formation of calcium carbonate (CaCO3) and water (H2O). This reaction is known as a precipitation reaction, where a solid substance (calcium carbonate) is formed from the combination of two aqueous solutions (calcium hydroxide and carbon dioxide gas).

The balanced chemical equation for the reaction between calcium hydroxide and carbon dioxide is as follows:

Ca(OH)2 + CO2 → CaCO3 + H2O

Explanation:
1. Calcium hydroxide (Ca(OH)2) is a strong base, and carbon dioxide (CO2) is an acidic gas. When they react, the base and acid neutralize each other, resulting in the formation of a salt (calcium carbonate) and water.
2. In the reaction, one molecule of calcium hydroxide reacts with one molecule of carbon dioxide to produce one molecule of calcium carbonate and one molecule of water.
3. The reaction is a double displacement reaction, where the calcium cation (Ca2+) from calcium hydroxide combines with the carbonate anion (CO3 2-) from carbon dioxide to form calcium carbonate. The hydroxide anion (OH-) from calcium hydroxide combines with a hydrogen cation (H+) from carbon dioxide to form water.
4. Calcium carbonate is an insoluble compound, and thus, it precipitates out of the solution as a solid.
5. The water formed during the reaction remains in the solution as a liquid.

Overall, the reaction between calcium hydroxide and carbon dioxide results in the formation of calcium carbonate and water. This reaction is commonly used in various applications, such as in the production of cement, as a pH regulator in water treatment, and in the preparation of lime water as a chemical indicator.