phenol Flashcards
What is phenol?
Phenol is benzene with a hydroxyl (-OH) group attached. It has the formula C6H5OH.
How does the –OH group affect phenol’s reactivity compared to benzene?
The addition of the –OH group makes phenol more reactive than benzene due to increased electron density by partially delocalising into the ring
What effect do hydroxyl (-OH) and amine (-NH2) groups have on substitution reactions in phenol?
They are electron-donating, increasing electron density at the 2, 4, and 6 positions, making these carbons more susceptible to electrophilic attack.
What effect do nitro (-NO2) groups have on substitution reactions in phenol?
Nitro groups are electron-withdrawing, decreasing electron density at the 2, 4, and 6 positions, leading to substitution at the 3 and 5 positions.
What happens when phenol reacts with alkalis?
Phenol is weakly acidic and reacts with alkalis to form a salt and water, resulting in a metal phenoxide.
What occurs during the electrophilic substitution of phenol with bromine?
The hydroxyl group directs substitution to the 2, 4, and 6 positions, forming 2,4,6-tribromophenol, which is insoluble and forms a white precipitate.
What is observed during the bromination of phenol?
A color change from orange to colorless occurs as bromine water reacts, with hydrogen bromide formed as a byproduct.
What is the product of phenol reacting with dilute nitric acid?
Phenol reacts with dilute nitric acid to form nitrophenol and water.
What structural isomers are formed from the nitration of phenol?
The nitration of phenol produces two structural isomers: 2-nitrophenol and 4-nitrophenol.
