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

Physical chemisty, Calculate the ratio of d number of molecules in two ener...

Calculate the ratio of d number of molecules in two energy levels at 27''c given E2=9.75x10"-13erg/mol E1=6.95X10"-13erg/mol g1=2 g2=3

Uses of pyrogallol, Uses of pyrogallol (a) As a developer in photograph...

Uses of pyrogallol (a) As a developer in photography. (b) As a hair dye. (c) In medicine of skin diseases like eczema. (d) For absorbing none reacted oxygen in gas ana

Oxidation and reduction, Definitions  Oxidation exactly meant 'combinat...

Definitions  Oxidation exactly meant 'combination with oxygen' and reduction 'removal of oxygen'. These definitions have been illustrated. Oxidation implies combination with a

What is the iupac name of carbon?, IUPAC name is given to compounds. Carbon...

IUPAC name is given to compounds. Carbon is an element so it will bw called as carbon only. eg. hydrocarbons - CH4=methane                            C2H6=Ethane

Explain toluene, Explain Toluene Toluene has added stability associate...

Explain Toluene Toluene has added stability associated with aromaticity; compound A, although conjugated, is not aromatic. Because any equilibrium favours the more stable comp

Explain the orientation of d-orbitals in organic chemistry., There are five...

There are five d-orbitals totally existed. These are designated as  d xy ,  d yz , ,  d xz ,  and . The shapes of these orbitals are explained below:      The three or

Mixture of he, A mol 4:1 mixture of He and CH4 is contained in vessel at 20...

A mol 4:1 mixture of He and CH4 is contained in vessel at 20 bar pressure.Due to a hole in the vessel the gas mixture leaks out.the composition of the mixture,effusing out initiall

What do you mean by nuclear fusion, Q. What do you mean by Nuclear Fusion? ...

Q. What do you mean by Nuclear Fusion? Ans. The idea of fusion is that two small unstable nuclei are smooshed together to make one larger stable nucleus. This is the type

Compounds of group 16 elements, Q. Compounds of Group 16 Elements? We w...

Q. Compounds of Group 16 Elements? We will now discuss some compounds like the hydrides, halides and oxides of the Group 16 elements.  All elements of this group form simple

Aromatic nitro compounds, why are aromatic nitro compounds pale yellow in c...

why are aromatic nitro compounds pale yellow in colour

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