rater. Plaster UI Paris is used for making toys, materials for decoration
nd for making surfaces smooth. Try to find out why is calcium sulphate
emihydrate called 'Plaster of Par?
Casoa
Q
E S T I O N S
2.
3.
What is the common name of the compound CaOCI,?
Name the substance which on treatment with chlorine yields bleaching
powder.
Name the sodium compound which is used for softening hard water.
What will happen if a solution of sodium hydrocarbonate is heated?
Give the equation of the reaction involved.
Write an equation to show the reaction between Plaster of Paris and
water.
5.
What you have learnt
Answers
Answer:
What is the common name of the compound CaOCI,?
Answer: Calcium Hypochlorite is an inorganic chemical compound with chemical formula CaOCl2. They are also called calcium oxychloride and the common name of CaOCl2 is bleching or chlorine powder.
Name the substance which on treatment with chlorine yields bleaching
powder.
answer b:- Calcium hydroxide[Ca(OH)2], on treatment with chlorine Cl2, yields bleaching powder.
Name the sodium compound which is used for softening hard water.
answer c:-The solution of sodium carbonate is alkaline .
What will happen if a solution of sodium hydrocarbonate is heated?
answer d:- When sodium hydrogen carbonate is heated we get sodium carbonate, water and carbon dioxide gas.
Give the equation of the reaction involved.
Write an equation to show the reaction between Plaster of Paris and
water.
answer e:-
Plaster of Paris when reacts with water liberating heat through crystallization. Gypsum is produced by heating plaster of paris to about 150-degree Celsius. When the dry plaster of paris powder is mixed with water it reforms into gypsum. Depending upon the temperature gypsum converts to hemihydrate or anhydrous form.
Plaster of Paris
CaSO
4
.
2
1
H
2
O
+
Water
2
3
H
2
O
⟶
Gypsum
CaSO
4
.2H
2
O