Q. What is this unknown compound? Additional info: During the sodium fusion test
ID: 1027241 • Letter: Q
Question
Q. What is this unknown compound? Additional info: During the sodium fusion test, with addition of AgNO3 there was no precipitate indicating the absence of a halogen. The refractive index was 1.3888 @ 20 degrees celsius. The boiling point of the first 10 drops during distillation was 31.4-47.8 degrees celsius and the second fraction of the distillate was at a range of 48.9-83.2 degrees celsius. During the solubility determination test, the unknown was NOT soluble in water, ether, HCl, NaOH, NaHCO3 and H2SO4.
Explanation / Answer
As the compound shows two ranges of boiling point, it should be a mixture of two compounds.
The IR spectra highly resembles that of mineral oil (Nujol). It supports the fact that it does not have halogen and not soluble in water, ether, HCl, NaOH, NaHCO3 and H2SO4. However, boiling point of nujol is high, >300 degree C. So, I am excluding this option.
Alternatively, the IR spectra can be of petroleum ether or cyclohexane.
Pet ether matches all other properties given by you, except solubility in ether. B.P. 42-62, RI 1.370, no halogen. Pet ether is soluble in ether.
Cyclohexane has B.P. 81, RI 1.43, no halogen. Again, this is miscible with ether.
Therefore, I think the unknown compund is a mixture of pet ether and cyclohexane. However, the solubility in ether information is incorrect.
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