Question

In: Chemistry

EXTRACTION EXERCISE. The Kd (coeficient of distribution) between Dietilic eter and Water is 1.0 if 50mg...

EXTRACTION EXERCISE. The Kd (coeficient of distribution) between Dietilic eter and Water is 1.0 if 50mg of A is dissolve on 1.0ml of water. How much of A is going to be extracted in a portion of 0.50ml of dietilic eter? How much of A is going to remain on the water? Remember Kd=1.0

Solutions

Expert Solution

Let x mg of A be extracted in diethyl ether. Therefore, concentration of A per mL of ether is (x mg)/(0.50 mL).

Mass of A remains in water = (50.0 – x) mg; the concentration of A per mL of water is (50.0 – x) mg/(1.0 mL).

The partition co-efficient Kd is defined as

Kd = concentration of A in ether/concentration of A in water

===> 1.0 = (x mg/0.50 mL)/(50.0 – x)mg/1.0 mL

===> 1.0 = x/0.50(50.0 – x)

===> 1.0*0.50*(50.0 – x) = x

===> 25.0 – 0.5x = x

===> 1.50x = 25.0

===> x = 25.0/1.50 = 16.6667 ≈ 16.67

The mass of A extracted in ether is 16.67 mg (ans).

The mass of A remaining in the water layer is (50.0 – 16.67) mg = 33.33 mg (ans).


Related Solutions

A water initially contains 50mg/L of Mg2+. The pH of the water is increased until the...
A water initially contains 50mg/L of Mg2+. The pH of the water is increased until the concentration of hydroxide ion is 0.0005 M. Calculate the concentration (mg/L) of magnesium ion in this water at this pH. Assume that the temperature of the solution is 25 degrees C.
Assume that the distribution coefficient (Kd) for Hg(II) is 104.9 (log Kd=4.9), the concentration of suspended...
Assume that the distribution coefficient (Kd) for Hg(II) is 104.9 (log Kd=4.9), the concentration of suspended sediments (Csed) is 10 mg L-1, the settling velocity (vs) of the silt-size particles is 4.17 cm hr-1, the area (A) of the water body is 50 km2 and the mean depth (H) is 6 m. What is the rate constant for removal of Hg(II) by scavenging, in units of per day?
In isolation, a DNA-binding protein binds to its regulatory sequence with a Kd of 1.0 microM....
In isolation, a DNA-binding protein binds to its regulatory sequence with a Kd of 1.0 microM. Another DNA binding protein binds to another sequence on the same DNA a few bases away with a Kd of 5.0 microM when alone. The two proteins each have a domain which binds to the other, with an interaction energy of -2.7 kcal/mole: (a) Draw the thermodynamic box which represents all four states of this system. (b) what are the affinities for each protein...
Give the comparison between continuous extraction with a technique called soxlet extraction.
Give the comparison between continuous extraction with a technique called soxlet extraction.
Predict whether or not extraction will work for the separation of the following using water and...
Predict whether or not extraction will work for the separation of the following using water and dichloromethane as the two immiscible solvents. Give a reason for your prediction. 1. Paraffin wax from sodium chloride. 2. Decane from pentaerytritol, C(CH2Oh)4 3. Sodium benzoate from sodium chloride. 4. 1-Pentanol from 1-heanol.
A weak base, B, (Kb=1.0 *10-7) equilibrates between water (phase 1) and benzene (phase2). a) Define...
A weak base, B, (Kb=1.0 *10-7) equilibrates between water (phase 1) and benzene (phase2). a) Define the distribution coefficient for this system b) Explain the difference between the partition coefficient, K, and the distribution coefficient, D, for this system. c) Calculate D at a pH of 9 if K=5.0 d) Will D be greater at pH of 10 than 9? Explain.
A suspension of 4-aminophenol (1.0 equivalent) in water (1 mL of water for every 2.7 mmol...
A suspension of 4-aminophenol (1.0 equivalent) in water (1 mL of water for every 2.7 mmol of 4- aminophenol) is heated at 65 °C to 75 °C for 5 minutes with stirring. Acetic anhydride (1.5 equivalents) is added, and the reaction is stirred for 10 minutes at 65 °C to 75 °C, and then an additional 10 minutes at room temperature. At this point, the crude target product begins to slowly precipitate from the solution. You can assume that your...
Solute A has a distribution coefficient of 9.0 between methylene chloride and water. Show that extracting...
Solute A has a distribution coefficient of 9.0 between methylene chloride and water. Show that extracting a solution containing 1.0 mole of A in 100. mL of water is more efficient if two 25 extractions with methylene chloride are performed rather than a single 50. mL extraction with methylene chloride.
A solvent-extraction process usingN,N − diethyldodecanamide, which is insoluble in water and has a density of...
A solvent-extraction process usingN,N − diethyldodecanamide, which is insoluble in water and has a density of 0.847 g / cm3 . In a typical experiment at 30°C, 50 g of 20 wt % citric acid and 80 wt % water was contacted with 0.85 g of amide. The resulting organic phase, assumed to be in equilibrium with the aqueous phase, contained 6.39 wt % citric acid and 2.97 wt % water. Determine the partition (distribution) coefficients for citric acid and...
A compound distributes between benzene (solvent 1) and water (solvent 2) with a distribution coefficient, K...
A compound distributes between benzene (solvent 1) and water (solvent 2) with a distribution coefficient, K = 2.7. If 1.0g of the compound were dissolved in 100mL of water, what weight of compound could be extracted by THREE sequential 10-mL portions of benzene? What weight of compound could be extracted if ONE 30-mL portion of benzene were used. If the distribution constant, K were 0.5, for the distribution of a compound between benzene (solvent 1) and water (solvent 2), and...
ADVERTISEMENT
ADVERTISEMENT
ADVERTISEMENT