(A) (a) Give the chemical name and formula of Plaster of Paris. (b) Write the chemical equation of its…
(A) (a) Give the chemical name and formula of Plaster of Paris.
(b) Write the chemical equation of its preparation.
(c) Give any two uses of it.
Solution
(A)
(a)
• Calcium sulphate hemihydrate
• CaSO4 . 2 H2 O
373K
(b) CaSO4 . 2H2 O → CaSO4 . 2 H2 O + 2 H2 O
(c) Plaster of Paris is used for
• making toys
• to support fractured bones in right position.
(or any other two uses)
OR
(B)
(a) Methanoic acid/ Formic acid/ HCOOH.
(b) (i) When acid is added to water, it does not cause
excessive local heating/ does not cause splash out and
burns.
(ii) Baking soda, being alkaline in nature, neutralises
excess acid in stomach and provides relief.