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

Illustrate kinetic molecular theory of gases, Q. Illustrate Kinetic Molecul...

Q. Illustrate Kinetic Molecular Theory of Gases? Ans. The behavior and properties of gases can be explained by the Kinetic Molecular Theory (KMT). A gas that behaves accord

Experiment, what is the function of the charcoal in the purification of the...

what is the function of the charcoal in the purification of the 4-nitroanine 2.why is it not possible to obtain 2-and 4-nitroaniline by direct nitration of aniline (phenylamine)

Melting points of s block, give the melting temperature values of group 2 e...

give the melting temperature values of group 2 elements

Illustrate Chemical nomenclature, Q. Illustrate Chemical nomenclature? ...

Q. Illustrate Chemical nomenclature? Ans. Chemical nomenclature is the system of names that chemists use to identify compounds precisely. The systematic method of naming c

What is the mechanism of e1cb?, E1cb means elimination, unimolecular, of th...

E1cb means elimination, unimolecular, of the conjugate base. This type elimination proceeds through the carbanion mechanism. An carbon compound, acting as an acid, is attacked by

Biomolecules - organic chemistry, Biomolecules All living bodies are ma...

Biomolecules All living bodies are made up of various lifeless substances that are availabe in their cells in a extremely complex but highly organized form. These are known as

PERIODIC TABLE, LIST METALIC AND NON METALIC ELEMENTS

LIST METALIC AND NON METALIC ELEMENTS

Covalent compounds are generally, Covalent compounds are generally ...... i...

Covalent compounds are generally ...... in water: (1) Soluble                                          (2) Insoluble      (3) Dissociated       (4) Hydrolysed Ans:

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