IUPAC name of  is:

(1) but-2-en-2,3-diol

(2) pent-2-en-2,3-diol

(3) 2-methylbut-2-en-2,3-diol

(4) hex-2-en-2,3-diol

But-2-ene exhibits cis-trans-isomerism due to

1. rotation around C₂-C₃ double bond

2. rotation around C₃-C₄ sigma bond

3. rotation around C₁-C₂ bond

4. restricted rotation around C=C bond

If optical rotation produced by the compound (i) is +52° then that produced by that the compound (ii) is:

1. -52°                2. +52°

3. 0°                   4. unpredictable

Which of the following pairs are enantiomers?                

1. 

2. 

3. 

4. 

In the following, the most stable conformation of n-butane is                

An alkane forms isomers if the number of carbon atoms is:

(a) $\ge$1                                   (b) $\ge$2

(c) $\ge$3                                   (d) $\ge$4

Which of the following has asymmetric carbon atom?

Stereoisomers (geometrical or opticals) which are neither superimposable nor mirror image to each other are called:

(1) enantiomers             

(2) mesomers

(3) tautomers               

(4) diastereomers

Diastereomers can be separated by:

(a) fractional distillation               (b) simple distillation

(c) electrophoresis                      (d) all of these

Which of the following pairs of carbon skeletons is an example of isomerism?