Two possible stereo-structures of CH₃CHOH.COOH, that are optically active, called:

1.	Diastereomers	2.	Atropisomers
3.	Enantiomers	4.	Mesomers

In which of the following compounds, the C—Cl bond ionization shall give the most stable carbonium ion?

1.		2.
3.		4.

The enolic form of ethyl acetoacetate is given below-

 

The number of σ and π bonds in the enolic form are respectively:

1. 18 sigma bonds and 2 pi-bonds
2. 16 sigma bonds and 1 pi-bond
3. 9 sigma bonds and 2 pi-bonds
4. 9 sigma bonds and 1 pi-bond

The structure of the compound whose IUPAC name is 3-Ethyl-2-hydroxy-4-methylhex-3-en-5-ynoic acid is:

1.		2.
3.		4.

The correct order of increasing bond length of  C-H, C-O, C-C and C=C is:

1.  $\mathrm{C}-\mathrm{C}<\mathrm{C}=\mathrm{C}<\mathrm{C}-\mathrm{O}<\mathrm{C}-\mathrm{H}$

2.  $\mathrm{C}-\mathrm{O}<\mathrm{C}-\mathrm{H}<\mathrm{C}-\mathrm{C}<\mathrm{C}=\mathrm{C}$

3.  $\mathrm{C}-\mathrm{H}<\mathrm{C}-\mathrm{O}<\mathrm{C}-\mathrm{C}<\mathrm{C}=\mathrm{C}$

4.  $\mathrm{C}-\mathrm{H}<\mathrm{C}=\mathrm{C}<\mathrm{C}-\mathrm{O}<\mathrm{C}-\mathrm{C}$

The most reactive compound towards electrophilic reagent among the following is:

1.		2.
3.		4.

The most stable conformation of n-butane among the following is:

1.		2.
3.		4.

The following compounds are given for reference
(1) CH₃-CH₂^–
(2) H₂C=CH^–
(3) HC≡C^– 

The increasing order of basic strength is:
1. (2)>(1)>(3)
2. (3) >(2) >(1)
3. (1) >(3) >(2)
4. (1) >(2)>(3)