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A chromatography column, packed with silica gel as stationary phase, was used to separate a mixture of compounds consisting of (A) benzanilide, (B) aniline and (C) acetophenone. When the column is eluted with a mixture of solvents, hexane : ethyl acetate (20:80), the sequence of obtained compounds is:

a. (B), (A) and (C) b. (C), (A) and (B) c. (B), (C) and (A) d. (A), (B) and (C)... View Article

In the following reaction sequence, structures of A and B, respectively will be:

Answer. a

The correct order of stability for the following alkoxides is:

a. (C) > (A) > (B) b. (C) > (B) > (A) c. (B) > (A) > (C) d. (B)... View Article

Which is the correct option for the following reactions

ks and ke are respectively the rate constants for substitution and elimination, and μ = ks/ke, the correct option is... View Article

What is the major product in the following reaction sequence

Answer: A During trisubstitution, the acetanilide group attached to the benzene ring is more electron donating than the methyl group... View Article

Which of these reactions are possible?

a. A and D b. B and D c. B, C and D d. A and B Answer: b In... View Article

For the reaction A_(l) →2B_(g) ∆U= 2.1 kcal, ∆S= 20 calK^-1 at 300 K, Hence ∆G in kcal is

Answer: -2.7 ∆H= ∆U + ∆ngRT ∆H= 2100 + (2 × 2 × 300) (R=2 calK-1mol-1) = 3300 cal ∆G=... View Article

The number of chiral carbons in chloramphenicol is:

Answer: 2

Chlorine reacts with hot and concentrated NaOH and produces compounds (X) and (Y). Compound (X) gives white precipitate with silver nitrate solution. The average bond order between Cl and O atoms in (Y) is

Answer: 1.67 Bond order = total no. of bonds / total resonating structures = 5/3 = 1.67.

During the nuclear explosion, one of the products is ⁹⁰Sr with half of 6.93 years. If 1 µg of ⁹⁰Sr was absorbed in the bones of a newly born baby in place of Ca, how much time, in years, is required to reduce it by 90% if it is not lost metabolically

Answer: 23.03 All nuclear processes follow first order kinetics, and hence T1/2 = 0.693 / λ λ = 0.1(year)-1 t... View Article

Two solutions A and B each of 100 L was made by dissolving 4 g of NaOH and 9.8 g of H₂SO₄ in water, respectively. The pH of the resulting solution obtained from mixing 40 L of Solution A and 10 L of Solution B is:

Answer: 10.6 Molarity of NaOH (4 g in 100 L) = 10-3 M Molarity of H2SO4 (9.8 g in 100... View Article

Consider the following reactions – Which of these reaction(s) will not produce Saytzeff product?

Which of these reaction(s) will not produce Saytzeff product? a) b and d b) d only c) a, c and... View Article

the electron gain enthalpy of fluorine chlorine bromine and iodine respectively are

a) -333, -325, -349 and -296 b) -333, -349, -325 and -296 c) -296, -325, -333 and -349 d) -349,... View Article

A solution of m-chloroaniline, m-chlorophenol and m-chlorobenzoic acid in ethyl acetate was extracted initially with a saturated solution of NaHCO₃ to give fraction A. The left over organic phase was extracted with dil. NaOH solution to give fraction B. The final organic layer was labelled as fraction C. Fractions A, B and C, contain respectively:

a) m-chlorobenzoic acid, m-chlorophenol and m-chloroaniline b) m-chlorophenol, m-chlorobenzoic acid and m-chloroaniline c) m-chloroaniline, m-chlorobenzoic acid and m-chlorophenol d) m-chlorobenzoic... View Article

Given that the standard potential; (Eo) of Cu²⁺/Cu and Cu⁺/Cu are 0.34 V and 0.522 V respectively, the E^o of Cu²⁺/Cu⁺ is :

a) +0.158 V b) -0.158 V c) 0.182 V d) -0.182 V Answer: a Cu2+ + 2e– Cu E° =... View Article

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