Multiple Choice QuestionsPlaster of Paris on making paste with little water sets to hard mass due to formation of
CaSO4
CaSO4.1/2 H2O
CaSO4 H2O
CaSO4.2H2O
A solution of sodium thiosulphate on addition of few drops of ferric chloride gives violet colour due to the formation of
Na2S4O6
Fe2(SO4)3
Fe2(S2O3)3
Fe2(S2O3)2
The chemical which is used for plastering the broken bones is
(CaSO4)2H2O
MgSO4·7H2O
FeSO4·7H2O
CuSO4·5H2O
A.
(CaSO4)2H2O
(a) (CaSO4)2H2O is plaster of Paris. Since, on adding water, it sets into a hard mass due to the formation of gypsum, it is used for plastering the broken bones.
(b) MgSO4·7H2O (epsom salt) shows deliquescence and efflorescence and used as a purgative in medicine.
(c) FeSO4·7H2O (green vitriol) is used for the preparation of Mohr's salt and in the ring test for nitrate ions.
(d) CuSO4·5H2O (blue vitriol) is used for electroplating and electrorefining of copper and for malting Bordeaux mixture, an excellent fungicide.
Solution of sodium thiosulphate in photography works as
to shine film
to develop film
to dissolve silver bromide
to change negative into positive
Which of the following is an organometallic compound?
Lithium methoxide
Lithium acetate
Lithium dimethylamine
Methyl lithium
Arrange Na+, Mg+ and Al3+ in increasing order of energy of hydration.
Na+ < Mg+ < Al3+
Al3+< Mg+ < Na+
Al3+ < Na+ < Mg2+
Mg2+< Al3+ < Na+
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