Page 5 - 3.LESSON NOTES-(CH-2 WASHING SODA& PLASTER OF PARIS)

 Properties of Plaster of Paris-

• Calcium sulfate is an odorless, white amorphous or crystalline solid.
• Its melting point is 1460 ºC and in higher temperature it decomposes.
• It is poorly soluble in water (0.21 g/100 mL at 20 ºC).
• It sets into a hard mass when mixed with water and left to dry.
(It reacts with water to give back Gypsum, which is the hard mass.)

CaSO4. ½ H2O + 1½ H2O -→ CaSO4.2H2O
POP Gypsum (hard mass)
 Uses of Plaster of Paris-

• It is commonly used to precast and hold parts of ornamental plaster work
placed on ceilings and cornices.

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