name of [Cr (C2O4)3]3-
[Co(NH3)3Cl3]
K2[Ni(CN)4]
[Co(en)3]cl3
urgent.
Answers
Nernst Distribution law
“At constant temperature, a solute distributes itself between two immiscible solvents only in a particular ratio”
This statement is a Nernst Distribution Law – i.e. the law that determines the relative distribution of a component that is soluble in two liquids, these liquids being immiscible or miscible to a limited extent. This law is one of the laws applying to ideal dilute solutions. It was discovered by W. Nernst in 1890. The Nernst distribution law states that, at equilibrium, the ratio of the concentrations of a third component in two liquid phases is constant. The law may be expressed in the form
c1/c2 = k
where c1 and c2 are the molar equilibrium concentrations of the third component in the first and second phase, respectively; the constant k is the distribution coefficient, which is temperature dependent.
The Nernst distribution law permits us to determine the most favorable conditions for the extraction of substances from solutions. If the dissolved compound in one of the solvents can associate:
nA
than the ration c1/c2 is not stable at constant temperature
Determination of the distribution coefficient of acetic acid in the system water – 1-butanol
Experimental equipment:
2M CH3COOH in 1-butanol
0.5 M NaOH
0.1 M NaOH
1-butanol
Phenolphthalein
0.1 M oxalic acid
6 storage bottle (100 ml)
6 separatory funnel
Titration flask
Pipettes
Measuring cylinder (100 ml)
Flow-sheet:
Preparation of the acetic acid solution in 1-butanol; volume 100 ml, the final concentrations: 1 M, 0.75 M, 0.5 M, 0.25 M, 0.1 M and 0.05 M.
Determination of the precise hydroxide sodium solution concentrations using the standard oxalic acid solution on phenolphthalein.
Pour 50 ml (by measuring cylinder) of the mixture (acetic acid + 1-butanol) into the separatory funnel and add identical volume of water; shake for 30 minutes
Stabilize the solution to get the good distribution of both phases
Determination of the acetic acid concentration: take out the sample of the precise amount from each phase, put it in the titration flask, add 20 ml water and titrate by sodium hydroxide on phenolphthalein up to steady pink color (take out 10 ml from water layer, 20 ml from butanol layer).
The amount from the water layer is 10 ml, from the butanol layer it is 20 ml
Evaluation:
Write down the data into the table.
cHAc
Vw NaOH
Vb NaOH
Cw
Cb
k
..........
..........
..........
For each concentration of acetic acid write down consumption in water and butanol phase, final concentrations and value of the distribution coefficient.
Calculate the average value and standard device from this value.