Extraction of f-block element, Chemistry

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.

Posted Date: 7/12/2013 6:41:47 AM | Location : United States

Related Discussions:- Extraction of f-block element, Assignment Help, Ask Question on Extraction of f-block element, Get Answer, Expert's Help, Extraction of f-block element Discussions

Write discussion on Extraction of f-block element
Your posts are moderated
Related Questions
General Tests of Esters (a) Esters has sweet smell (b)  Esters is neutral towards litmus (c) A pink colour is developed while one or two drops of phenolphthalein are adde

Q. Test for the presence of linseed oil? Hexabromide test is done to know the extent of presence of linolenic acid. In presence of fish oils, which are rich in linolenic acid,

Q. Analytical tests for fats and oils? The analytical tests used in fats and oils are to: • determine the nature of fat or oil or the blends to see whether it is of the typ

If the water molecules in 1g of water were uniformly distributed on earth surface , how many such water molecules would there be in 1 cm^2 of earth? Solution) No. of molecules in

Ask qwhy is 5-bromovanillin the major productuestion #Minimum 100 words accepted#

reaction of ammonium molybdate with phosphate power point

which is more acidic 3 floro pentonoic acid or 3 nitro pentonoic acid

Principal functional group-Polyfunctional Organic Compounds If the organic compound includes two or more functional groups, one of the functional sets is chosen as the princ