What is plaster of Paris write its preparation and properties?
It is a white powder. When mixed with water (1/3 of its mass), it evolves heat and quickly sets to a hard porous mass within 5 to 15 minutes. During setting, a slight expansion (about 1%) in volume occurs so that it fills the mould completely and takes a sharp impression.
What is the properties of plaster of Paris?
PLASTER OF PARIS is non-flammable and non-combustible. Has generally low chemical reactivity but can act as an oxidizing agent under extreme conditions. Decomposes at high temperature to generate toxic oxides of sulfur. Reacts exothermically but slowly with moisture in the air or water to form gypsum CaSO4.
What is plaster of Paris how it is prepared give its important uses?
This is prepared by heating gypsum to 120–130°C. Uses of plaster of Paris: (i) It is used in making chalks and fire proof materials. (ii) Used for making patient plasters used in surgery and for plastering fractured parts of the body.
How is plaster of Paris prepared Class 11?
Plaster of Paris is manufactured by heating gypsum at 423K or 150o C/300o F. On heating gypsum at 423 K, it loses water molecules and becomes calcium sulphate hemihydrate. This product is known as the plaster of Paris.
What is plaster of Paris write its two main properties?
Properties of Plaster of Paris.
(i) It is white powder. (ii) When it is mixed with water, crystals of gypsum are produced and set into hard mass. … (iii) When Plaster of Pairs is heated at 473 K, if forms anhydrous calcium sulphate which is known as dead burnt plaster of paris.
What are the properties of Plaster of Paris Class 10?
Properties of Plaster of Paris
(1) It is a white powder. (2) It has a very remarkable property of setting into a hard mass on wetting with water. P.O.P. should be stored in a moisture proof container.
What is plaster of paris write to main properties and two uses?
Calcium sulfate hemihydrate (CaSO4. 2H2O), known as plaster of Paris. Used in making casts and patterns for molds and statues. Used as the cement in ornamental casting and for making decorative materials.
What is plaster of Paris Class 11 chemistry?
CBSE NCERT Notes Class 11 Chemistry The S Block Elements. The chemical name of Plaster of Paris is Calcium Sulphate (CaSO4·½ H2O)). It is obtained by heating the gypsum, CaSO4·2H2O, to 393 K. It forms a plastic mass on addition of water which further gets hardened within 5-15 minutes.
How is plaster of Paris prepared write chemical equation and two important?
The name plaster of Paris came from the fact that it was first of all made by heating gypsum which was mainly found in Paris. The compound plaster of Paris is prepared by heating gypsum at 120oC. The chemical formula for the plaster of Paris is (CaSO4) H2O and is better known as calcium sulfate hemihydrate.
How is plaster of Paris prepared Why is temperature control necessary during its preparation How does it react with water?
It loses 3/4th of its water of crystallisation and forms plaster of Paris as seen in the Equation above. b) The Temperature should be controlled carefully b/w 393 – 403K, otherwise above this temperature (say 473K), the whole of the water of Hydration is Lost and the Gypsum gets dead burnt.