Feasibility of acid-base reactions

28 questions on Feasibility of acid-base reactions from the General Organic Chemistry II: Acids and Bases chapter: 5 NEET level, 11 JEE Main, 12 JEE Advanced. Each one opens with its answer and solution.

• Which reagent can be used to distinguish a carboxylic acid such as C6H5COOH from a simple phenol such as C6H5OH by a simple test tube reaction? NEET level
• Which of the following aqueous solutions dissolves phenol by forming a salt? NEET level
• Terminal alkynes (pK_a approx 25) can be converted almost completely into sodium alkynides by which of the following? NEET level
• In an acid-base equilibrium HA + B- <=> A- + HB, the equilibrium lies on the side of NEET level
• Which of the following compounds gives brisk effervescence when added to aqueous sodium hydrogencarbonate? NEET level
• Take pK_a(H2CO3) = 6.4. Which of the following reactions does NOT proceed appreciably in the forward direction? JEE Main level
• Using pK_a(CH3COOH) = 4.76 and pK_a(H2O) = 15.7, the value of log_10K for CH3COOH + OH- <=> CH3COO- + H2O is closest to JEE Main level
• Given pK_a(C6H5OH) = 10.0 and pK_a(C2H5OH) = 15.9, what is log_10K for C6H5OH + C2H5O- <=> C6H5O- + C2H5OH? JEE Main level
• An ether solution contains benzoic acid, phenol and toluene. It is shaken with dilute aqueous NaHCO3 (pK_a of H2CO3 is 6.4; benzoic acid 4.20; phenol 10.0). The... JEE Main level
• Given pK_a(HC#CH) = 25 and pK_a(C2H5OH) = 15.9, the value of log_10K for HC#CH + C2H5O- <=> HC#C- + C2H5OH is JEE Main level
• Which base converts a simple ketone such as acetone (pK_a approx 19.3 in water) almost completely into its enolate? JEE Main level
• Methylmagnesium bromide, CH3MgBr, evolves methane by acid-base reaction (ignore any addition reactions) with which of the following? JEE Main level
• Take pK_a(H2CO3) = 6.4. Which of the following acids liberate CO2 from aqueous NaHCO3? (pK_a values: 2,4,6-trinitrophenol 0.4; 2-nitrobenzoic acid 2.17; 4-nitro... JEE Main level
• An ether solution of aniline, phenol and naphthalene is shaken with dilute aqueous HCl. Which compound passes into the aqueous layer? JEE Main level
• Acetylacetone (pK_a = 9.0) reacts with carbonate ion: CH3COCH2COCH3 + CO3^2- <=> CH3COCHCOCH3^- + HCO3-. Given pK_a(HCO3-) = 10.3, calculate log_10K for this re... JEE Main level
• Use the following data: pK_a of H2CO3 6.4, benzoic acid 4.20, phenol 10.0, ethanol 15.9, H2O 15.7, NH3 38. Which statements are correct? JEE Advanced level
• An acid HA reacts with phenoxide ion: HA + C6H5O- <=> A- + C6H5OH, with equilibrium constant K = 4.0 x 10^5. Given pK_a(C6H5OH) = 10.0, the pK_a of HA is closes... JEE Advanced level
• An ether solution of benzoic acid, phenol, aniline and naphthalene is extracted first with aqueous NaHCO3, then with aqueous NaOH, then with dilute HCl. The aqu... JEE Advanced level
• Using pK_a values: HC#CH 25, C6H5OH 10.0, CH3COOH 4.76, C2H5OH 15.9, NH3 38, H2O 15.7, H2CO3 6.4, H2 35, which of the following acid-base reactions has the larg... JEE Advanced level
• Ethyl acetoacetate has pK_a = 10.7. For which bases is the conversion of ethyl acetoacetate into its enolate essentially complete (take log K geq 4)? (pK_a of c... JEE Advanced level
• An amide RCONH2 has N-H pK_a approx 17. Which of the following bases deprotonates it essentially completely (conjugate acids: H2O 15.7, C2H5OH 15.9, H2CO3 6.4, ... JEE Advanced level
• 4-Hydroxybenzoic acid (HO-C6H4-COOH; carboxylic acid pK_a 4.58, phenolic OH pK_a 9.3 after the carboxylate has formed) is treated with an excess of (i) aqueous ... JEE Advanced level
• A compound HOOC-CH2-CH(OH)-CH2-C#CH (3-hydroxyhex-5-ynoic acid) is treated with excess CH3MgBr. Considering only acid-base reactions, how many moles of CH4 are ... JEE Advanced level
• Carbon dioxide is bubbled separately through (I) aqueous sodium phenoxide and (II) aqueous sodium benzoate. Given pK_a: H2CO3 6.4, phenol 10.0, benzoic acid 4.2... JEE Advanced level
• The reaction C6H5OH + CH3COO- <=> C6H5O- + CH3COOH is considered with pK_a(C6H5OH) = 10.0 and pK_a(CH3COOH) = 4.76. Which statements are correct? JEE Advanced level
• Assertion (A): Sodium acetylide is formed from ethyne with NaNH2 but not appreciably with NaOC2H5 in ethanol. Reason (R): pK_a of NH3 (38) is much higher than t... JEE Advanced level
• Take pK_a: H2 35, phenol 10.0, ethanol 15.9, ethyne 25, NH3 38. For which of the following is deprotonation by NaH thermodynamically unfavourable (log K < 0)? JEE Main level
• Acetone has pK_a = 19.3. Conjugate-acid pK_a values: ethanol 15.9, H2 35, diisopropylamine 36, NH3 38. Which bases convert acetone essentially completely into i... JEE Advanced level