In: Chemistry
Limonene contains 
 double bond. Hence, it gives positive tests with bromine and
KMnO4. Tests with bromine and KMnO4 are for alkenes. These tests
suggests that Limonene contains 
 double bond.
Eugenol contains 
 double bond. Hence, it gives positive tests with bromine and
KMnO4. Tests with bromine and KMnO4 are for alkenes. These tests
suggests that Eugenol contains 
 double bond.
Eugenol also contains phenolic -OH group. Phenolic -OH group gives positive test with FeCl3. Positive test with FeCl3 suggests that Eugenol contains phenolic -OH group.
