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RAJ Vs KOL Eliminator Match - Team (23.05.18)

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Venue:  Eden Gardens, Kolkata Date & Time: 23rd, May, 07:00 PM  Rajasthan Royals (All Players): Ajinkya Rahane (c), Stuart Binny, Ben Laughlin, Jaydev Unadkat, Sanju Samson, Ish Sodhi, Krishnappa Gowtham, Rahul Tripathi, Shreyas Gopal, Heinrich Klaasen (w), Jofra Archer, Dhawal Kulkarni, Anureet Singh, Ankit Sharma, Dushmantha Chameera, Prashant Chopra, Jatin Saxena, Mahipal Lomror, D Arcy Short, Aryaman Birla, Sudhesan Midhun Kolkata Knight Riders (All Players) : Dinesh Karthik (c), Sunil Narine, Chris Lynn, Robin Uthappa, Nitish Rana, Andre Russell, Shubman Gill, Shivam Mavi, Javon Searles, Prasidh Krishna, Kuldeep Yadav, Rinku Singh, Mitchell Johnson, Tom Curran, Piyush Chawla, Vinay Kumar, Ishank Jaggi, Apoorv Wankhade, Cameron Delport Probable Players RAJASTHAN : Ajinkya Rahane (c), Heinrich Klaasen (w), Stuart Binny, Ben Laughlin, Jaydev Unadkat, Sanju Samson, Ish Sodhi, Krishnappa Gowtham, Rahul Tripathi, Shreyas Gopal, Jofra Archer KOLKATA...
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Extraction

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1. Define selectivity

The effectiveness of solvent B for separating a solution of A and C in to components is measured by comparing the ratio of C to A in the B rich phase to that in A rich phase at equilibrium. For all useful extraction operations the selectivity must exceed unity, the more so better. It varies considerably with solute concentrations. If the selectivity is unity, no separation is possible.

2. State the applications of liquid extraction


  • Metal separations such as uranium-vanadium,,zirconium and tungsten-molybdenum and the fission products of atomic energy processes are more economical by liquid extraction
  • Many pharmaceutical products eg:- penicillium is produced in mixtures so complex that only liquid extraction is a feasible separation device
  • Long chain fatty acids can be separated by high vacuum distillation from vegetable oils but more economically by extraction with liquid propane. 

3. Write the properties of good solvent


  • The solvent should be non-toxic, non-flammable and of low cost
  • Viscosity, vapor pressure & freezing point should be low for ease in handling & storage
  • The solvent should be inert toward the other components of the system and towards common material of construction 
  • The solvent should be easily recoverable.

4. Define extract and raffinate

In extraction operation, the solution which is to be extracted is called feed and the liquid with which the feed is contacted is called solvent, the solvent rich product of operation is called extract, the residual liquid from which solute has been removed is raffinate.

5. Define double solvent with example

Many complicated extraction processes may use two solvent to separate the components of feed such process is called double solvent or fractional extraction Eg:- a mixture of P- and O- nitrobenzoic acids can be separated by distributing them between insoluble liquids chloroform dissolves water and ortho isomer is dissolved in water.

6. Define plait point

In system of three liquids one pair is partially soluble , the plait point P is defined as last of tie line and point where A rich & B rich solubility curves merges is ordinarily not at the maximum value of consolubility curve.

7. What are the factors to be selected while choosing a solvent for extraction

The following are the factors to be considered for selecting a solvent

  •  Selectivity
  •  Distribution coefficient
  •  Insolubility of solvent
  •  Density
  •  Recoverability
  •  Inter-facial tension
  •  Chemical reactivity
  •  Viscosity, vapor pressure, freezing point
  •  Toxicity, cost 

8. Define isotherms

The common type of system extraction is water (A) – chloroform (B) –acetone (C) and benzene (A) –water (B) – acetic acid (C).the triangular coordinates are called isotherms. The coordinates A ,B ,C in diagram of triangle at constant temperature is called isotherm.

9. What is solutropic system

In a few extraction systems , the direction of tie line slope changes and one tie line will be horizontal . Such systems are said to be solutropic system.

10. Write about distribution coefficient

The ratio of y*/x is distribution coefficient usually greater than unity. It is ratio at equilibrium larger values of distribution coefficient are desirable since less solvent will then be required for extraction.

11. What is equilateral-triangular coordinates

Equilateral-triangular coordinates are used extensively in chemical literature to describe graphically the concentrations internally systems. It is the property of an equilateral-triangle that the sum of the perpendicular distances from any point within the triangle to three sides equals the altitude of triangle.

12. Give details about multi-component systems

The simplest system of four components occur when two solutes distribute between two solvent. Eg:- the distribution of formic and acetic acids between the partly soluble solvents water and carbontetrachloride.

13. Write about solvent recovery by extraction

Most processes use distribution or evaporation to recover the solvent from the product solutions of liquid extraction it is not uncommon to recover solvent by liquid extraction. Eg:- recovery of penicillium from acid feed fermentation both in which it occurs by extraction with amyl-acetate as solvent followed by stripping of penicillium from the solvent by extracting it in to an aqueous buffer solution.

14. Define stage efficiency

The performance of individual extraction stages can be described in terms of the approach to equilibrium actually realized by effluent extract and raffinate streams.