Already have an account? Get multiple benefits of using own account!
Login in your account..!
Remember me
Don't have an account? Create your account in less than a minutes,
Forgot password? how can I recover my password now!
Enter right registered email to receive password!
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.
styx code of B4H10
A 64-g sample of germanium-66 is left undisturbed for 12.5 hours. At the end of that period, only 2.0 g remain. What is the half-life of this material? 4. With a half-life of 28.8
Derive Nerst equation for both anode and cathode.
Unsaturated dicarboxylic acids The molecular formula of the simplest unsaturated dicarboxylic acid is HOOC.CH=CH.COOH This formula, however represents two chemical compounds, m
Acid dyes: These are commonly salts of sulphonic acids and can be helpful to silk, wool and nylon. The presence of sulphonic acid group creates them water soluble. These dyes a
names
Physical properties of Acetone - Aldehydes and Ketones (a) Acetone is a colourless liquid with characteristic pleasant odour. (b) Acetone is inflammable liquid. It boils at
GFAAS is often necessary to add modifiers in order to increase the sensitivity of the techniques.Giving example explain the principles used in the selection of such modifiers,be ca
Why can classical (Werner) octaedral complexes with no pi-bonding have between 12-22 valence electrons, whereas octahedral complexes with pi-bonding must have 18 electrons?
what is migratory aptitude in rearrangement reactions
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!
whatsapp: +91-977-207-8620
Phone: +91-977-207-8620
Email: [email protected]
All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd