Final answer:
To distinguish between ethanol and phenol, the ferric chloride test can be used, whereas the Lucas test is effective for differentiating between propanol and 2-methylpropan-2-ol. Phenol will react with ferric chloride to give a violet color, and 2-methylpropan-2-ol will react faster than propanol in the presence of hydrochloric acid and zinc chloride, indicating its presence.
Step-by-step explanation:
Simple Chemical Tests for Compound Identification
To distinguish between ethanol and phenol, one could use the ferric chloride test. Ethanol does not react with ferric chloride, but phenol forms a violet complex with ferric chloride, thereby indicating its presence. Similarly, to differentiate between propanol and 2-methylpropan-2-ol (isobutanol), the Lucas test can be used. In this test, 2-methylpropan-2-ol reacts faster than propanol with hydrochloric acid and zinc chloride to form a cloudy solution. The rate of reaction is linked to the degree of steric hindrance around the hydroxyl group.
Another test for phenol is its ability to turn blue litmus paper to red, demonstrating its acidic nature compared to ethanol which is neutral and will not affect the color of the litmus paper. Furthermore, sodium metal reacts vigorously with alcohols to produce hydrogen gas, but phenol is less reactive due to the stability of the phenoxide ion.
For the Lucas test, propanol, being a primary alcohol, reacts slower and will form a clear solution over a longer period, while 2-methylpropan-2-ol reacts almost immediately due to its tertiary alcohol structure. This difference in reactivity helps distinguish between the two compounds.
These tests ultimately exploit the chemical reactivity differences between different types of alcohols and phenols, providing a clear and simple method to identify them. Therefore, the correct options for distinguishing the compounds are the ferric chloride test for ethanol and phenol, and the Lucas test for propanol and 2-methylpropan-2-ol.