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.
what is rayon?what are the things made of it?
ENTROPY Entropy is a thermodynamic property of a system. It is denoted as S and like as the enthalpy and internal energy, it is a state function. In thermodynamic expression, e
The hydration of propene The hydration of propene includes the usual mechanistic steps of alkene protonation to form a carbocation followed by the nucleophilic reaction of wate
A reaction is of first order in reactant A and of second order in reactant B. How is the rate of this reaction affected when (i) the concentration of B alone is increased t
Pick out the isoelectronic structures from the following : CH + 3 , H 3 O + NH 3 CH - 3 I
Q. Beneficiation of Ores? Most of the ores available in nature contain large amounts of impurities, i.e. gangue. Direct extraction of metals from the ores by metallurgical proc
Strategy 3 Two levels of wheat flour 3960g and 3940g and two levels of baking powder 60g and 40g are selected to be tested. In all trials the percentages of A, B and C are fix
Preparation of saturated calomel electrode and determination of standard potentials of electrodes such as Cu 1 Cu, Zn 1 Zn, etc. Comparison of the potential values with values from
For which of the following sets of four quantum numbers, an electron will have the highest energy: n l m s
Structure of benzene - Kekule structure It has a special structure, which is even though unsaturated even then it usually behave as a saturated compound. (i) Kekule's struct
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