How many structures of F are possible?

(1) 2

(2) 5

(3) 6

(4) 3

The optically active alkane with lowest molar mass is:

1. ${\mathrm{CH}}_3{\mathrm{CH}}_2\mathrm{C}\equiv \mathrm{CH}$

2. ${\mathrm{CH}}_3{\mathrm{CH}}_2-\stackrel{{\mathrm{CH}}_3}{\stackrel{|}{\mathrm{CH}}}-{\mathrm{CH}}_3$

3. 

4. ${\mathrm{CH}}_3{\mathrm{CH}}_2.{\mathrm{CH}}_2{\mathrm{CH}}_3$

a-D-(+)-glucose and β-D-(+)-glucose are :

(1) enantiomers

(2) conformers

(3) epimers

(4) anomers

The absolute configuration of 

 is:

(1) S, R                 

(2) S, S

(3) R, R                 

(4) R, S

The correct statement regarding electrophile is

Which of the following statements is true regarding the conformers of ethane?

The IUPAC name of the compound

is-

1. 3-Keto-2-methylhex-4-enal

2. 5-Formylhex-2-en-3-one

3. 5-Methyl-4-oxohex-2-en-5-al

4. 3-Keto-2-methylhex-5-enal

The correct order of acidity among the following is:

1. CH₂=CH₂ >CH≡CH > CH₃C≡CH > CH₃-CH₃

2. CH≡CH > CH₃-C≡CH > CH₂=CH₂ >CH₃-CH₃

3. CH≡CH > CH₂=CH₂ > CH₃-C≡CH > CH₃-CH₃

4. CH₃-CH₃ > CH₂=CH₂ > CH₃-C≡CH > CH≡CH

The most suitable method of separation of 1:1 mixture of ortho and para-nitrophenols is

1. sublimation

2. chromatography

3. crystallisation

4. steam distillation

In pyrrole,

The electron density is maximum on

1. 2 and 3         2. 3 and 4

3. 2 and 4         4. 2 and 5