Lime and Chlorine are used to make bleaching powder.

Bleaching powder, also known as calcium hypochlorite, is a chemical compound that is widely used for bleaching, disinfection, and water treatment purposes. It is a white powder with a strong smell of chlorine.

The process of manufacturing bleaching powder involves the following steps:

1. Preparation of Slaked Lime:
- Slaked lime, also known as calcium hydroxide, is prepared by adding water to quicklime (calcium oxide).
- The chemical equation for this reaction is: CaO + H2O → Ca(OH)2.
- Quicklime is obtained by heating limestone (calcium carbonate) in a lime kiln, which decomposes it to calcium oxide and carbon dioxide.

2. Chlorination:
- In this step, chlorine gas (Cl2) is passed through the slaked lime.
- The reaction between chlorine and slaked lime results in the formation of bleaching powder.
- The chemical equation for this reaction is: 2 Cl2 + 2 Ca(OH)2 → Ca(ClO)2 + CaCl2 + 2 H2O.

3. Drying and Packaging:
- The obtained bleaching powder is then dried to remove any moisture content.
- It is then packaged and stored in airtight containers to prevent contact with moisture and air, as this can lead to the decomposition of bleaching powder.

Bleaching powder is a powerful oxidizing agent and has strong bleaching properties. It releases chlorine gas when it comes in contact with water, which acts as a disinfectant and bleaching agent. It is widely used for disinfecting drinking water, treating wastewater, and as a bleaching agent in industries such as textiles and paper.

In conclusion, bleaching powder is made from lime (calcium hydroxide) and chlorine gas. The reaction between these two chemicals produces calcium hypochlorite, which is the active ingredient in bleaching powder.