The element which on burning in air gives peroxide is
lithium
sodium
rubidium
caseium
B.
sodium
Alkali metals on burning in air give monoxide, peroxide or superoxide.
Li forms monoxide
2Li + O2 → Li2O
Na form peroxide as well as monoxide
2Na + O2 → Na2O2
2Na + O2 → Na2O
K, Rb and Cs from superoxide
M (= K, Rb, Cs) + O2 → MO2
Plaster 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
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+