Plaster of Paris Reaction with Water:
Plaster of Paris, also known as calcium sulfate hemihydrate, is a white powdery substance that reacts with water to form a hard solid. This reaction is known as hydration and is an exothermic reaction, meaning it releases heat.

Hydration Process:
When plaster of Paris is mixed with water, it undergoes a chemical reaction where water molecules surround each calcium sulfate molecule. This causes the calcium sulfate to lose its crystal water and form a solid mass. The reaction can be represented by the following equation:
CaSO4 · 1/2H2O + 1.5H2O → CaSO4 · 2H2O
(Plaster of Paris) + (Water) → (Gypsum)

Setting Time:
The reaction between plaster of Paris and water is relatively quick, and the mixture begins to harden within a few minutes. The setting time can be adjusted by altering the water-to-plaster ratio. A higher amount of water will result in a longer setting time, while less water will accelerate the process.

Physical Properties:
Once the plaster of Paris has fully set, it forms a solid mass known as gypsum. Gypsum is a white, smooth material with a porous structure. It is commonly used in construction, art, and medical applications due to its ability to be molded and shaped when wet, and its strength and durability when dry.

Relation to Bleaching Powder, Baking Soda, and Washing Soda:
- Bleaching Powder: Bleaching powder, also known as calcium hypochlorite, is not directly related to the reaction between plaster of Paris and water. It is a different compound used for disinfection and bleaching purposes.
- Baking Soda: Baking soda, or sodium bicarbonate, is also unrelated to the reaction. It is a compound used in cooking, cleaning, and various other applications.
- Washing Soda: Similarly, washing soda, or sodium carbonate, is not related to the reaction between plaster of Paris and water. It is commonly used in laundry detergents and as a cleaning agent.

In conclusion, when plaster of Paris reacts with water, it undergoes a hydration process, forming solid gypsum. This reaction is quick and releases heat. Plaster of Paris has various applications due to its ability to be molded and shaped when wet, and its strength and durability when dry. It is important to note that the reaction between plaster of Paris and water is separate from the properties and uses of bleaching powder, baking soda, and washing soda.

It forms gypsum...as
CaSo4.1/2H2O+ 3/2= CaSo4. 2H2O