What is formula of Slaked lime?

Question

Accepted Answer

The correct option is (4):

Slaked lime is the common name for calcium hydroxide, which has the chemical formula $Ca(OH)_2$. It is produced by a chemical process known as "slaking" quicklime (calcium oxide) with water. This reaction is represented as $CaO + H_2O \rightarrow Ca(OH)_2$. Calcium hydroxide is a white, powdery substance that is sparingly soluble in water, forming a basic solution. It has numerous applications, including in agriculture to neutralize acidic soils, in water treatment to adjust pH, and in construction as a component of mortar and plaster. Its alkaline nature makes it useful in various industrial and domestic processes.

The incorrect option is (1): $CaCO_3$ is the chemical formula for calcium carbonate, commonly known as limestone, marble, or chalk. While it is a calcium compound, it is not slaked lime and does not share its chemical properties or uses.

The incorrect option is (2): CaO represents calcium oxide, which is also known as quicklime or burnt lime. Quicklime is the raw material from which slaked lime is produced when it reacts with water, but it is not slaked lime itself.

The incorrect option is (3): $CaCl_2$ is the chemical formula for calcium chloride. This compound is a salt, often used as a desiccant or for de-icing roads, and it is chemically distinct from slaked lime.