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Fe is made passive by :
(c)
Formation of a thin layer of oxide upon the surface of metal, which protects the inner surface of metal to come in direct contact of air or other chemicals for reaction.
The iron salt used in blue prints is:
Which has highest melting point?
The colour of KMnO4 is due to
In KMnO4, Mn has no d-electron and colour is due to charge transfer spectra
Which of the following element does not show the variable oxidation state?
Pseudo transition element have 10 electro in d subshell , so cannot lose electron from d subshell.
With F highest stable oxidation state of Mn is
MnF4
Mn has 2 s electrons and five d. The s electrons can be unpaired to the 4p orbital..But almost three d orbitals can be used to form sigma bonds
Why?..
dz2 and dx2-y2 are the only two orbitals axially oriented and suited for head on sigma overlap…the other orbitals ar oriented in between axes . So they can only form pi bonds.
However…atmoat 1 non axial d orbital can be used so that just enough limiting stability is present in the molecule so formed as the involvement of Pi character in a sigma bond weakens it.
Cr2O72-+XCr3++H2O + oxidized product of X, X in the above reaction cannot be
SO42- can't be oxidised because S has highest oxidation state i.e. +6
The basic oxide is:
Lesser is the oxidation state of Cr in oxide, more is the basic nature.
The pair having similar magnetic moment is
Mn2+ and Fe3+both have 5 unpaired electrons. So, they have same magnetic moment
Lanthanoid which is radioactive is
In lanthanoid only Promethium (Pm) 61 is radioactive
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