Explore BrainMass

Identifying An Unknown Liquid And Precipitate

This content was STOLEN from BrainMass.com - View the original, and get the already-completed solution here!

A high-boiling bp = 202 - 204 degrees C, burns with a yellow, sooty flame. Sodium fusion indicates that halogens, nitrogen and sulfur are not present. It is not soluble in water, dilute sodium bicarbonate solution, or dilute hydrochloric acid. However, it proved to be soluble in 5% aqueous sodium hydroxide solution. The compound gives a purple color with ferric chloride solution and precipitate when reacted with bromine-water. Treatment with hydroxylamine reagent did not give a reaction, but a white precipitate was obtained when the compound was treated with alpha-napthyl isocyanate. On drying, this white, solid derivative had a melting point of 127 - 129 degrees C.

Identify the original liquid and write a structure for the solid derivative. After identifying the unknown liquid can you indicate what the structure of the precipitate obtained on reaction with bromine might be?

© BrainMass Inc. brainmass.com October 24, 2018, 6:36 pm ad1c9bdddf

Solution Preview

Yellow sooty flame indicates little oxygen and fairly high organic content-Many liquids burn with a characteristic flame. An aromatic hydrocarbon burns with a yellow, sooty flame. Aliphatic hydrocarbons burn with yellow flame but much less sooty. As the oxygen content increases the flame becomes more and more blue. Think of methanol flames which are ...

Solution Summary

This solution is comprised of a step by step explanation of how to identify a liquid and its precipitate based on chemical properties such as color of the flame, solubility, and treatment with hydroxylamine reagent.

See Also This Related BrainMass Solution

Identify the Unknown Liquid

A colorless liquid, bp = 199-201 degrees C, burnes with a yellow, sooty flame. The sodium fusion test proved negative for the presence of halogens, nitrogen, and sulfur. It was not soluble in water, 5% aqueous sodium hydroxide, or 5% hydrochloric acid. However, it dissolved in sulfuric acid with evolution of heat. It did not give a precipitate with 2,4-dinitrophenylhydrazine solution, and it did not decolorized bromine-methylene chloride solution. The unknown liquid did give a positive hydroxamate test and was found to have saponification equivalent of 136. Identify the unknown liquid.

View Full Posting Details