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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) Answer: b Since the column is eluted with the solvent having... View Article

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

Answer. a... View Article

The correct order of stability for the following alkoxides is:

a. (C) > (A) > (B) b. (C) > (B) > (A) c. (B) > (A) > (C) d. (B) > (C) > (A) Answer: b Higher the delocalization of... 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 a. μA > μB and ke(A)... 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 aryl halides, due to the partial double bond character generated by chlorine,... 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= ∆H - T∆S ∆G= 3300 – (300 × 20) = -2.7 kcal.... View Article

The number of chiral carbons in chloramphenicol is:

Answer: 2... View Article

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.... View Article

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 = (2.303/ λ) (log (a0)/at) 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 L) = 10-3 M Equivalents of NaOH= M × V × nf = 10-3 × 40... 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 d d) c only Answer: d... 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, -333, -325 and -296 Answer: b Cl > F >... 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,... 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° = 0.340 V Cu - Cu+ + e- E°= -0.522 V Cu2+ + e- ⇾ Cu+ E° = ?... View Article

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