1
MCQ (Single Correct Answer)

AIPMT 2015 Cancelled Paper

Consider the following compounds :

Hyperconjunction occurs in
A
III only
B
I and III
C
I only
D
II only

Explanation

Only structure (III) has $$\alpha $$-H in conjugation with free radical.

So, hyperconjugation is possible in III only.
2
MCQ (Single Correct Answer)

AIPMT 2015 Cancelled Paper

In which of the following compounds, the C$$-$$Cl bond ionisation shall give most stable carbonium ion?
A
B
C
D

Explanation

Tertiary butyl chloride will give the most stable tertiary carbonium ion among the other given compounds due to hyperconjugation.
3
MCQ (Single Correct Answer)

AIPMT 2015 Cancelled Paper

The enolic form of ethyl accetoacetate as shown below has
A
9 sigma bonds and 2 pi-bonds
B
9 sigma bonds and 1 pi-bond
C
18 sigma bonds and 2 pi-bonds
D
16 sigma bonds and 1 pi-bond.

Explanation

The given structure has 18$$\sigma $$ bonds and 2$$\pi $$ bonds.
4
MCQ (Single Correct Answer)

AIPMT 2015 Cancelled Paper

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
A
16.75
B
15.76
C
17.36
D
18.20

Explanation

Wt. of organic substance = 0.25 g

V1 = 40 mL, T1 = 300 K

P1 = 725 – 25 = 700 mm of Hg

P2 = 760 mm of Hg (at STP)

T2 = 273 K

$${{{P_1}{V_1}} \over {{T_1}}} = {{{P_2}{V_2}} \over {{T_2}}}$$

V2 = $${{700 \times 40 \times 273} \over {300 \times 760}}$$ = 33.52 mL

Percentage of nitrogen

= $${{28 \times 33.52 \times 100} \over {22400 \times 0.25}}$$

= 16.76%

EXAM MAP

Joint Entrance Examination

JEE Advanced JEE Main

Graduate Aptitude Test in Engineering

GATE CE GATE ECE GATE ME GATE IN GATE EE GATE CSE GATE PI

Medical

NEET

CBSE

Class 12