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

Which of the following is least soluble: (1) BeF 2                                              (2)  NaBr                  (3)  CaF 2                              (4

Q. Explain the structure of Alkenes? Ans. Alkenes have the general formula C n H 2n . Therefore, for every n carbon atoms, there are 2n hydrogen atoms. Alkenes have C =

What are properties of an ideal electrical insulating material? The following are properties of an ideal (electrical) insulating material: (i)  Low  dielectric  court(high  die

If 0.5 mol of BaCl 2 is mixed with 0.20 mol of Na 3 PO 4 , the maximum amount of Ba 3 (PO4) 2 that can be formed is 3 BaCl 2 + 2 Na3PO 4 = Ba 3 (PO4) 2 + 6NaCl Here cle

quality of soya milk



The rate constant for a reaction of Zero order in A is 0.0030 mol L¯¹ s¯¹. How long will it take for the initial concentration of A to fall from 0.10 M to 0.075 M?

A single covalent bond is build when two atoms share a pair of electrons. Triple and double bonds can be formed when two or three such pairs are shared. A Lewis structure is a repr