Separations and Purifications Test 1
Passage I (Questions 1–7)
A student attempted to synthesize N-
phenylphthalimide according to the following reaction:
Phthalic acid Analine
N - Phenylphthalimide
Phthalic acid and aniline were heated to reflux for
one hour. Upon cooling, the mixture was dissolved in
ether and placed in a separatory funnel. The solution was
then washed with 5% aqueous Na2CO3 followed by 5%
aqueous HCl and allowed to stand over solid anhydrous
Na2SO4 for 15 minutes. The ether was then evaporated
and a solid product obtained.
The crude product was dissolved in an appropriate
hot solvent and after slowly cooling the solution, crystals
were obtained, which after filtering and drying gave a
melting point of 205¡ to 207¡C. The literature value for
the melting point of the expected product is 208¡C.
The recrystallized product was analyzed by thin layer
chromatography (TLC) and the chromatogram in Figure 1
A second student carried out the same reaction and
obtained the TLC chromatogram shown in Figure 2.
The solubility of the product in several solvents at
two different temperatures was also determined. These
results are presented in Table 1.
Solvent Solubility (g/100mL)
1. In the experiment, which of the following would have
been removed by washing the solution with sodium
A. Phthalic acid
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