Question Bank Directory

The half-life of a certain enzyme catalysed reaction is 138 s, that follows 1st order kinetics. The time required for the concentration of the substance to fall from $1.28 \text{ mg L}^{-1}$ to $0.04 \text{ mg L}^{-1}$, is:

Given below are two statements: **Statement I:** The product of the reaction of phenol with bromine depends on the nature of the solvent. **Statement II:** The reaction of phenol with bromine in $CHCl_3$ gives a monosubstituted bromo derivative whereas the reaction of phenol with bromine water yields a trisubstituted bromo derivative of phenol. In light of the above statements, choose the most appropriate answer from the options given below:

Identify A, X, Y, and Z in the reaction sequence involving Ethanal (A): 1. A → X (Reduction) 2. A → Y (Aldol Condensation) 3. A → Z (Reaction with Semicarbazide)

The compound, among the following, that will not be soluble in sodium hydrogen carbonate is:

A yellow precipitate with iodine and alkali is given by:

Reagents that can be used to convert alcohols to carboxylic acids are: (A) $CrO_3 - H_2SO_4$ (B) $K_2Cr_2O_7 + H_2SO_4$ (C) $KMnO_4 + KOH/H_3O^+$ (D) $Cu, 573 K$ (E) $CrO_3 + (CH_3CO)_2O$ Choose the most appropriate answer from the options given below:

Which of the following compounds with molecular formula, C₅H₁₀ yields acetone on ozonolysis?

An organic compound X having molecular formula $C_5H_{10}O$ yields phenyl hydrazone and gives a negative response to the iodoform test and Tollen's test. It produces n-pentane on reduction. X could be:

Propanoic acid with $Br_2/P$ yields a dibromo product. Its structure would be:

What is the correct order of the carboxylic acids' strength for the compounds labeled I, II, and III?

Predict the products in the given reaction (Reaction Scheme Missing)

An acid that forms an anhydride (X) on heating and an acid imide (Y) on strong heating with ammonia is:

Reaction of a carbonyl compound with one of the following reagents involves nucleophilic addition followed by the elimination of water. The reagent is:

Colostrum the yellowish fluid, secreted by mother during the initial days of lactation is very essential to impart immunity to the new born infants because it contains

CH_3CHO and C_6H_5CH_2CHO can be distinguished by:

The correct order of reactivity of phenyl magnesium bromide (PhMgBr) with the following compounds will be: I, II, III

A biconvex lens has radii of curvature, $20\text{ cm}$ each. If the refractive index of the material of the lens is $1.5$, the power of the lens is

The correct order of decreasing acid strength of trichloroacetic acid (A), trifluoroacetic acid (B), acetic acid (C), and formic acid (D) is:

The hydrolyzed product of an ester, when reduced by $LiAlH_4$, gives:

In which of the following pairs of molecules/ions, the central atoms have $sp^2$ hybridization?