Extraction of f-block element, Chemistry

Assignment Help:

Q. Extraction of f-block element ?

As all the lanthanides occur together in nature, their extraction involves two main steps: (i)   separation from one another and (ii) reduction of their compounds to metals. Since the lanthanides are all typically trivalent and are almost identical in size, their chemical properties ark almost similar. Thus, the separation of lanthanides from one another is a very difficult task, almost as difficult as the separation of isotopes. Only europium and cerium will be separated from the remaining lanthanides by employing conventional  Q+  chemical methods because of stabilities of Ce 4+and EU2+ in aqueous solution. Cerium can be separated from a mixture of lanthanides by oxidising ce3+ to ce4+ with permanganate or bromate or hypochlorite in an alkaline medium and subsequently precipitating it as Ce02.  Europium can be reduced to EU2+ either by electrolytic reduction with a mercury cathode or by using zinc amalgam. It is then precipitated from the solution as EuSo4.

Earlier the lanthanides used to be separated from each other by selective precipitation or by fractional crystallisation. With a limited amount of a precipitating agent, the substance uhichis least soluble is precipitated first. For example, if a base is added to a solution of  lanthanide nitrates, the least soluble Lu(OH)3 is precipitated first and the most soluble -  La(OH)3 last. As only a partial separation is effected, the precipitate is redissolved and the method is repeated several times.


Related Discussions:- Extraction of f-block element

Noble gases, NOBEL GASES With their closed-shell electron design the nob...

NOBEL GASES With their closed-shell electron design the noble gas elements of group 18 were long regarded as chemically inert. However, in 1962 Bartlett pinpoint that the ioniza

Two similar non-metallic atoms, The electron pair which forms a bond betwee...

The electron pair which forms a bond between two similar non-metallic atoms will be: (1) Dissimilar shared between the two (2) By complete transfer from one atom to other

Interconversion of the resonance structures, Interconversion of the resonan...

Interconversion of the resonance structures of carbon monoxide with the curved-arrow notation: Because the carbon in the structure on the left has a sextet of electrons, it

Molarity and normality, When 100 ml of M/10 H2SO4 is mixed with 500 ml of M...

When 100 ml of M/10 H2SO4 is mixed with 500 ml of My/10 NaOH then nature of resulting solution and normality of excess reactant left is

The energy of an electron of 2py orbital, The energy of an electron of 2py...

The energy of an electron of 2py  orbital is: (1) Greater than that of 2p x   orbital (2) Less than that of 2p x   orbital (3) Equal to that of 2s   orbital (4) Same a

Organic chemistry, Alkyl halide on reaction with dry silver oxide

Alkyl halide on reaction with dry silver oxide

Thermodynamic equilibrium constant, Q. For a homogeneous reaction in which ...

Q. For a homogeneous reaction in which the reactants and products are solutes in a solution, write a rigorous relation between the standard molar reaction enthalpy and the temperat

The electronic configuration & atomic number, The electronic configuration ...

The electronic configuration (outermost) of Mn +2   ion (atomic number of Mn= 25  ) in its ground state is: (1) 3d 5 , 4s o                          (2) 3d 4 , 4s 1   (3

Chemical properties proteins - oxidation, Chemical Properties Proteins - Ox...

Chemical Properties Proteins - Oxidation Oxidation : Proteins are oxidised on putrefaction and burning. The products comprise amines, nitrogen, carbon dioxide and water. The un

Explain bond dipole for dimethylmagnesium, Explain bond dipole for dimethyl...

Explain bond dipole for dimethylmagnesium The bond dipole for dimethylmagnesium should show that C is at the negative end of the C-Mg bond, because carbon is more electronegati

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd