Chemistry : Organic Chemistry – Some Basic Principles and Techniques

Which of the following molecules is least resonance stabilized?

The IUPAC name of neopentane is

• 2-methylbutane

• 2, 2-dimethylpropane

• 2-methylpropane

• 2-methylpropane

The electrophile, E^⊕ attacks the benzene ring to generate the intermediate σ-complex. Of the following, which σ-complex is of lowest energy? 

Which one of the following is the correct statement?

• Boric acid is a protonic acid

• Beryllium exhibits coordination number of six

• Chlorides of both beryllium and aluminium have bridged chloride structures in solid phase

• Chlorides of both beryllium and aluminium have bridged chloride structures in solid phase

Amount of oxalic acid present in a solution can be determined by its titration with KMnO₄ solution in the presence of H₂SO₄. The titration gives unsatisfactory result when carried out in the presence of HCl, because HCl

• gets oxidised by oxalic acid to chlorine

• furnishes H+ions in addition to those from oxalic acid

• reduces permanganate to Mn²⁺

• reduces permanganate to Mn²⁺

The correct decreasing order of priority for the functional groups of organic compounds in the IUPAC system of nomenclature is

• −COOH, −SO₃H, −CONH₂, −CHO

• −SO₃H, −COOH, −CONH₂, −CHO

• −CHO, −COOH, −SO₃H, −CONH₂

• −CHO, −COOH, −SO₃H, −CONH₂

CH₃Br + Nu^- → CH₃ -Nu +Br-
The decreasing order of the rate of the above reaction with nucleophiles (Nu–) A to D is
[Nu–=
(A) PhO^–
(B) AcO^–
(C) HO^–
(D) CH3O^–
]

• D > C > A > B

• D > C > B > A

• A > B > C > D

• A > B > C > D

The increasing order of stability of the following free radicals is

Due to the presence of an unpaired electron, free radicals are:

• Chemically reactive

• Chemically inactive

• Anions

• Anions

The decreasing order of nucleophilicity among the nucleophiles

• (a), (b), (c), (d)

• (d), (c), (b), (a)

• (b), (c), (a), (d)

• (b), (c), (a), (d)