CBSE
Lanthanides and actinides are also called :
short periods
inner-transition elements
long periods
main transition elements
Enrichment of U235 is done by
IF7
CIF3
IF3
ClF5
The diamagnetic species is
[Ni(CN)4]2-
[Ni(Cl)4]2-
[CoCl]2-
[CoF6]3-
Which is not true statement ?
Ions of d-block elements are coloured due to d-d transition
Ions of f-block elements are coloured due to f-f transition
[Sc(H2O)6]3+ , [Ti(H2O)6]4+ are coloured complexes
Cu+ is colourless ion
The reaction between metallic silver and aqueous NaCN forming a soluble complex occurs in the presence of :
nitrogen
oxygen
helium
chlorine
In first transition series, which element show maximum oxidation states :
Co
Mn
Cr
Fe
The most paramagenetic is :
Cr3+
Co2+
Mn2+
Fe2+
In presence of acidic medium, KMnO4 converts H2S into
Mn only
MnS only
MnS + S
S only
Which one is colourless ?
Co2+
Ni2+
Fe3+
Cu+
Colour imparted by Co(II) compounds to glass is
green
brown
violet
blue