Phenols: acidity, Kolbe, Reimer-Tiemann, electrophilic substitution

37 questions on Phenols: acidity, Kolbe, Reimer-Tiemann, electrophilic substitution from the Alcohols, Phenols and Ethers chapter: 8 NEET level, 13 JEE Main, 16 JEE Advanced. Each one opens with its answer and solution.

• Which one of the following gives a violet colour with neutral FeCl3 solution? NEET level
• Phenol is treated with excess bromine water. The product is NEET level
• Phenol is heated with CHCl3 and aqueous NaOH at about 340 K, and the product is acidified with H3O+. The main product is NEET level
• Which of the following is the strongest acid? NEET level
• Sodium phenoxide is heated with CO2 at 4-7 atm and about 400 K, and the product is then acidified with H3O+. The main product is JEE Main level
• Phenol is nitrated with dilute HNO3 at 298 K, giving a mixture of two mononitrophenols. When the mixture is steam distilled, the compound that distils over is JEE Main level
• Given pK_a values: phenol 10.0, 4-methylphenol 10.3, 3-nitrophenol 8.4, 4-nitrophenol 7.2. The decreasing order of acidity is JEE Main level
• Phenol is heated with CCl4 and aqueous NaOH, and the mixture is then acidified. The main product is JEE Main level
• Salicylic acid is warmed with ethanoic anhydride and a few drops of conc. H2SO4 to make aspirin. The group of salicylic acid that is acetylated is JEE Main level
• Aqueous NaHCO3 is added separately to solutions of phenol, benzoic acid and 2,4,6-trinitrophenol (picric acid, pK_a approx 0.4). Effervescence of CO2 is seen wi... JEE Main level
• A mixture of 3.76 g of phenol and 5.00 g of cyclohexanol is shaken with excess bromine water. Only the phenol reacts, giving a precipitate of 2,4,6-tribromophen... JEE Advanced level
• Which reagents can be used to distinguish phenol from cyclohexanol? JEE Advanced level
• Which of the following reactions of phenol give the product stated? JEE Advanced level
• Which statements about nitrophenols are correct? JEE Advanced level
• Which conversions of phenol can be achieved in a single step? JEE Advanced level
• Which statements about the Reimer-Tiemann reaction of phenol with CHCl3 and aqueous NaOH are correct? JEE Advanced level
• Which statements about salicylic acid are correct? JEE Advanced level
• Phenol is heated with NaOH and CO2 at 400 K and 5 atm, and then acidified to give A. A is warmed with ethanoic anhydride in the presence of a trace of acid to g... JEE Advanced level
• Benzene is treated with 2-chloropropane and anhydrous AlCl3 to give A. A is oxidised with air and then treated with dilute H2SO4 to give B and C. B is treated w... JEE Advanced level
• Which of the following is the most acidic? NEET level
• Phenol is heated with CHCl3 and aqueous NaOH, and the mixture is then acidified with H3O+. The major product is NEET level
• The electrophile that attacks the phenoxide ring in the Reimer-Tiemann reaction (CHCl3 with aqueous NaOH) is NEET level
• When phenol is treated with excess bromine water at room temperature, the product is NEET level
• Arrange in decreasing order of acidity: 4-nitrophenol, phenol, 4-methylphenol, cyclohexanol. JEE Main level
• Sodium phenoxide is heated with CO2 at 4-7 atm and 400 K, and the product is then treated with dilute H2SO4. The major product is JEE Main level
• Phenol is nitrated with dilute HNO3 at 298 K, giving a mixture of two mononitrophenols that can be separated by steam distillation. The compound that distils ov... JEE Main level
• Which of the following reactions of phenol are correctly stated? (Select all that apply.) JEE Main level
• The pK_a values are: phenol 9.95, 3-nitrophenol 8.36, 4-nitrophenol 7.15. The best explanation of why 4-nitrophenol is more acidic than 3-nitrophenol is that JEE Main level
• Cumene hydroperoxide, C6H5-C(CH3)2-O-OH, on treatment with dilute acid gives JEE Main level
• Which of the following are more acidic than phenol? JEE Main level
• A mixture contains 9.4 g of phenol and 10.8 g of 4-methylphenol. It is treated with excess bromine water. Assume every ring position ortho or para to the -OH gr... JEE Advanced level
• Phenol is treated with NaOH, then with CO2 (4-7 atm, 400 K), and acidified to give X. X is then heated with ethanoic anhydride in the presence of a few drops of... JEE Advanced level
• Phenol is converted to its sodium salt with NaOH and treated with CH3I to give P. P is nitrated with conc. HNO3/conc. H2SO4 at low temperature, and the para iso... JEE Advanced level
• 2-Hydroxybenzoic acid (salicylic acid) is treated as indicated. Select all correct statements. JEE Advanced level
• 4-Methylphenol is heated with CHCl3 and aqueous NaOH, and then acidified. Considering only the normal Reimer-Tiemann product (formyl group on the ring), the maj... JEE Advanced level
• Assertion (A): 2-Nitrophenol is steam volatile whereas 4-nitrophenol is not. Reason (R): 2-Nitrophenol has intramolecular hydrogen bonding, whereas 4-nitropheno... JEE Advanced level
• Which of the following statements about 2,4,6-trinitrophenol (picric acid) are correct? JEE Advanced level