Which of the following is the most stable carbocation?

1.              2. 

 

3.  ${\left({\mathrm{CH}}_3\right)}_3 \stackrel{+}{\mathrm{C}}$         4.  ${\mathrm{CH}}_2=\mathrm{CH}-\stackrel{\oplus }{\mathrm{C}}{\mathrm{H}}_2$

 

Calculate the stereoisomers of the given molecule :

CH₃CH=CHCH₂C HBrCH₃

1. 4

2. 6

3. 8

4. 2 

Lassaigne's extract is boiled with conc. HNO₃ while testing for halogens. By doing so, it:

1. Helps in the precipitation of AgCl

2. Increases the solubility product of AgCl

3. Increases the concentration of NO₃^- ions

4. Decomposes Na₂S and NaCN, if formed.

In Duma's method of estimation of nitrogen 0.35 g of an organic compound gave 55 ml of nitrogen collected at 300 K temperature and 715 mm pressure. The percentage composition of nitrogen in the compound would be

(Aqueous tension at 300 K-15 mm)

1. 16.45

2. 17.45

3. 14.45

4. 15.45

In pyrrole

the electron density is maximum on

1. 2 and 3         2. 3 and 4

3. 2 and 4         4. 2 and 5

Hydrogen cyanide and hydrogen isocyanide are:

1. Tautomers

2. Positional isomers

3. Metamers

4. Chain isomers

The number of different amines corresponding to the formula C₃H₉N is:

1. 2

2. 3

3. 4

4. 5

The number of optical isomers of pent-3-en-2-ol is:

1. 2             

2. 4

3. 8             

4. 16

Buta-1,3-diene and But-2-yne are:

1. Position isomers

2. Functional isomers

3. Chain isomers

4. Tautomers

Sulphur trioxide is:

1. An electrophile             

2. A nucleophile

3. A homolytic agent         

4. A base