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

1.	Chromatography	2.	Crystallization
3.	Steam distillation	4.	Sublimation

The IUPAC name of the compound     is:

1. 5-formylhex-2-en-3-one
2. 5-methyl-4-2-en-5-el
3. 3-keto-2-methylhex-5-enal
4. 3-keto-2-methylhex-4-enal

The correct statement regarding electrophile is :

The correct order with respect to –I effect of the substituents is:
(R = alkyl)

1. –NH₂ > –OR < –F
2. –NR₂ < –OR < –F
3. –NH₂ > –OR > –F
4. –NR₂ > –OR > –F

The most stable carbocation among the following is:

1.	`	2.
3.		4.

In Duma's method for estimation of nitrogen, 0.25 g of an organic compound gave 40 mL of nitrogen collected at 300 K temperature and 725 mm pressure. If the aqueous tension at 300 K is 25 mm, the percentage of nitrogen in the compound is:

Hyperconjugation occurs among the following compounds:

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

In Kjeldahl’s method for estimation of nitrogen present in the soil sample, ammonia evolved from 0.75g of sample neutralized 10ml of 1M H₂SO₄. The percentage of nitrogen in the soil is: