# Home work

Would you please answer as much as you can from the following questions:

Q1.

#### How many pages is this assigment?

A). Mention the main drawbacks of theory of solvent extracti

B). What is the volume of chloroform required to decrease the concentration of Malathion pesticide in water sample (50 mL) at 100 ppm concentration level at the optimum experimental conditions to 1.0×10-8 M assuming D = 90. What the extraction percentage will be if the volume of the organic solvent is doubled. Comments in your results.

C). What is the volume of MIBK required to decrease the concentration of iron (III) in water (0.2 L) as [Fe(CNS)6]3- to 0.5 percent from its original value in the presence of selective onium ion-pair reagent. Assuming D = 125. What the extraction percentage will be the volume of the organic solvent is doubled.

D). A water sample (100 mL) contained pesticide at concentration 50ppm. Calculate the amount of the pesticide remaining in the aqueous phase after:
i. A single extraction with 50.0 ml of n- hexane,
ii. A double successive extraction with 25.0 ml of the same solvent.
Iii After five successive extraction with 10.0 ml hexane,
Assume the distribution ratio (D) of the analyte between water and n- hexane equal 65. Comment on your data.

Q2.

A). Discuss the role of primary ion in the ion exchange chromatography.

B). Prove the equation:
D=Kd/ (1+ Kb/OH-)
for the removal of organic base contaminate from industrial wastewater samples by liquid-liquid extraction.

C). Account for:
i. In separation of acidic contaminates from water by solvent extraction, the extraction medium should be strong acidic.
ii. The ion exchange should be denser than water and contains large number of accessible active sites
iii. In the flow mode of separation the performance decrease at high flow rate

D). What is the concept of the followings?

i. Distribution ratio (D) and distribution coefficient (Kd) in liquid – liquid and liquid-solid extraction.
ii. Chelating agent referring to the optimum conditions of proper chelating used in solvent extraction.
iii. Resolution and symmetry factors in HPLC and GC techniques.

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