A white powder is used by doctors to support fractured bones.
(a) Write the name and chemical formula of the powder.
(b) How is this powder prepared ?
(c) When this white powder is mixed with water, a hard solid mass is
obtained. Write a balanced chemical equation for the change.
(d) Give one more use of this white powder.
Answers
A white powder is used by doctors to support fractured bones.
A) The name of the white powder is "Plaster of Paris" or simply known as the POP.
The chemical formula of POP is,CaSO4.2H2O (hydrated calcium sulphate).
B) Normally POP is made by the heating process of gypsum or the dihydrated calcium sulphate.
C)The chemical reaction between POP and water is:
CaSO4.½H2O + 1½H2O =CaSO4 .2H2O
D) POP is also used for several construction works and for making several pottery items.
Answer:
(a) calcium sulphate hemihydrate
caso4 . 1/2h2o
(b) caso4 . 1/2h2o ---> caso4 . 2h2o
(c) When calcium sulphate hemi-hydrate or plaster of paris (CaSO4.1/2H2O) is mixes with water it turns into calcium sulphate di-hydrate which is a white hard solid mass.
(d)This powder is used for construction word and making pottery items