Among the lathanides the one obtained by synthetic method is
Lu
Pm
Pr
Gd
Cinnabar is an ore of
Hg
Cu
Pb
Zn
In the silver plating of copper, K[Ag(CN)2] is used instead of AgNO3. The reason is
a thin layer of Ag is formed on Cu
more voltage is required
Ag+ ions are completely removed from solution
less availability of Ag+ ions, as Cu cannot displace Ag from [Ag(CN)2]- ion
Which one of the following is an ore of silver ?
Argentite
Stibnite
Haematite
Bauxite
Which one of the following forms a colourless solution in aqueous medium ?
V3+
Cr3+
Ti3+
Sc3+
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
Nitriding is the process of surface hardening of steel by treating it in an atmosphere of
NH3
N2
O3
H2S
In which of the following compounds transition metal has zero oxidation state ?
[Fe(CO)5]
NH2 . NH2
NOClO4
CrO5
Actinides
are all synthetic elements
include element 104
have any short lived isotopes
have variable valency
