Lab Report: Solubility and Acid-Base Properties of Organic Compounds (Exp. 2) 40 pts/max
NAME: Shawn Vuong
SECTION: 145
Part 4: Classification of an Unknown Organic Compound by its Acid/Base Properties.
Unknown Number: #6
Identity of Unknown (alkane, alcohol, amine, or carboxylic acid):
Amine (10 pts)
Experimental Evidence: The compound was non soluble in water. When put on blue
indicator paper, paper stayed blue. When put on red indicator paper, paper stayed red.
This suggested that the unknown organic compound was both, non polar and neutral.
Then compound did not dissolve in 10% hydrochloric acid or in 10% aqueous sodium
hydroxide. Finally added compound to the concentrated sulfuric acid and compound
turned a copper color and bubbled. Also the reaction gave off heat. This was similar to
the reaction in part 3 with dimethylaniline and the concentrated sulfuric acid. (20 pts)
Question. para-Cresol has low solubility in water but is much more soluble in 10% NaOH (aq). On
the other hand anisole, an isomer of para-cresol, has low solubility in both water and 10% NaOH
(aq). Give a reasonable explanation to account for these observations.
(10 pts)
H3C
OH
para-cresol
O
CH3
anisole
 Both para-cresol and anisole must be non-polar molecules, or not polar enough to dissolve in water
fully dissolve in water. But in para-cresol the OH group makes the molecule acidic, which causes it to
dissolve in a base. On the other hand anisole has the methyl group in place of the hydrogen in its isomer
para-cresol. Therefore it will not be giving up any hydrogen and will not be acidic and as a result does not
dissolve in the basic solution sodium hydroxide.