Which one of the following characteristics of the transition metals is associated with their catalytic activity ?
Colour of hydrated ions
Variable oxidation states
High enthalpy of atomisation
Paramagnetic behaviour
The most durable metal plating on iron to protect against corrosion is
Nickel plating
Tin plating
Copper plating
Zinc plating
Which of the following elements is responsible for oxidation of water to O2 in biological processes ?
Fe
Cu
Mn
Mo
Cinnabar is an ore of
Hg
Pb
Zn
Among the lathanides the one obtained by synthetic method is
Lu
Pm
Pr
Gd
Actinides
are all synthetic elements
include element 104
have any short lived isotopes
have variable valency
General electronic configuration of lanthanides are
(n-2) f1-14(n-1)s2 p6d0-1ns2
(n-2) f10-14(n-1)d0-1ns2
(n-2) f0-14 (n-1)d10ns2
(n-2)d0-1 (n-1) f1-14 ns2
The lanthanide contraction is responsible for the fact that
Zr and Yt have about the same radius
Zr and Nb have similar oxidation state
Zr and Hf have about the same radius
Zr and Zn have the same oxidation state
CuSO4 when reacts with KCN forms CuCN, which is insoluble in water. It is soluble in excess of KCN, due to formation of the following complex
K2[Cu(CN)4]
K3[Cu(CN)4]
Cu(CN)2
Cu[K Cu(CN)4]
Which of the following has more unpaired d-electrons ?
Zn+
Fe2+
N3+
Cu-
