Chemistry : Organic Chemistry – Some Basic Principles and Techniques

Among the following carbocations:

Ph₂C⁺CH₂Me (I), PhCH₂CH₂CH⁺Ph (II), Ph₂CHCH⁺Me (III) and Ph₂C(Me)CH₂ (IV), the order of stability is:

• IV > II > I > III

• I > II > III > IV

• II > I > IV > III

• I > IV > III > II

Which one of the following will show optical isomerism?

• OH-CH₂-CO₂H

• CH₃-CH(OH)-CO₂H

• (CH₃)₂-CH-CO₂H

• (CH₃)₂-C(Cl)-CO₂H

Among the following statements about the molecules X and Y, the one(s) which correct is (are)

• X and Y are diastereomers

• X and Y are enantiomers

• X and Y are both aldohexoses

• X is a D-sugar and Y is an L-sugar

Explain why aniline is not as basic as ammonia.

The two structures written below represent

• pair of diastereomers

• pair of enantiomers

• same molecule

• both are optically inactive

Which of the following carbocations will be most stable ?

• ${\mathrm{Ph}}_3{\mathrm{C}}^{+}$

• ${\mathrm{CH}}_3-\stackrel{+}{\mathrm{C}}{\mathrm{H}}_2$

• $({\mathrm{CH}}_3{)}_2\stackrel{+}{\mathrm{C}}\mathrm{H}$

• ${\mathrm{CH}}_2=\mathrm{CH}-\stackrel{+}{\mathrm{C}}{\mathrm{H}}_2$

A compound is formed by substitution of two chlorine for two hydrogens in propane. The number of possible isomeric compounds is

• 4

• 3

• 2

• 5

1 mole of methyl amine on reaction with nitrous acid gives at NTP

• 1.0 L of nitrogen

• 22.4 L of nitrogen

• 11.2 L of nitrogen

• 5.6 L of nitrogen

The major product P in the following reaction is

CH₃-CH=CH₂ $\underset{\mathrm{Peroxide}}{\overset{\mathrm{HI}}{\to }}$ P

• CH₃CH₂CH₂I

• CH₃-CH(I)-CH₃

• CH₂(I)-CH=CH₂

• CH₂(I)-CH₂(I)

Which of the following will exhibit cis-trans isomerism?

• CH₂Br-CH₂Br

• CBr₃ - CH₃

• CHBr = CHBr

• CBr₂= CH₂