1. Xtra Edge February 2012 - Career Point

Passage # 2 (Ques. 17 to 19)
An activating group activates all positions of the
benzene ring; even the positions meta to it are more
reactive than any single position in benzene itself. It
directs ortho and para simply because it activates the
ortho and para positions much more than it does the
meta.
A deactivating group deactivates all positions in the
ring, even the positions meta to it. It directs meta
simply because it deactivates the ortho and para
positions even more than it does the meta. Thus, both
ortho and para orientation and meta orientation arise
in the same way : The effect of any group whether
activating or deactivating is strongest at the ortho and
para positions.
But certain groups (– NH2 and – OH, and their
derivatives) act as powerful activators towards
electrophilic aromatic substitution, even though they
contain electronegative atoms and can be shown in
other ways to have electron-withdrawing inductive
effects.
Halogens are unusual in their effect on electrophilic
aromatic substitution; they are deactivating yet ortho,
para-directing. Deactivation is characteristic of
electron withdrawal, whereas ortho-para orientation
is characteristic of electron release.
17. Which will undergo Friedel-Crafts alkylation
reaction?
(1)
(3)
CH3
NO2
COOH
(2)
(4)
CH2CH3
OH
(A) 1, 2 and 4 (B) 1 and 3
(C) 2 and 4 (D) 1 and 2
18. Which of the following is the strongest acid ?
OH
(A) OH
(C)
OH
NO2
NO2
(B)
(D)
Cl
OH
NO2
19. Reactivity in halogen substituted benzene rings is
controlled by :
(A) resonance
(B) inductive effect
(C) inductive effect dominates resonance effect
(D) resonance effect dominates inductive effect
This section contains 3 questions (Questions 20 to 22).
Each question contains statements given in two columns
which have to be matched. Statements (A, B, C, D) in
Column I have to be matched with statements (P, Q, R, S)
in Column II. The answers to these questions have to be
appropriately bubbled as illustrated in the following
example. If the correct matches are A-P, A-S, B-Q, B-R,
C-P, C-Q and D-S, then the correctly bubbled 4 × 4
matrix should be as follows :
P Q R S
A P Q R S
B P Q R S
C P Q R S
D P Q R S
Mark your response in OMR sheet against the question
number of that question in section-II. + 6 marks will be
given for complete correct answer and No Negative
marks for wrong answer. However, 1 mark will be
given for a correctly marked answer in any row.
20. One mole of an ideal gas is subjected to the following
process :
Column-I Column-II
(A) ∆W = 0 (P) If the gas undergoes
free expansion
(B) ∆E = 75Cv (Q) If the gas is cooled
reversibly at constant
pressure from 373 K
to 298 K
(C) ∆H = –75 Cp (R) If the gas is heated
from 298 K to 373 K
reversively at constant
pressure
(D) ∆W = –75 R (S) If the gas is heated
from 298 K to 373 K at
constant volume
21. Match the Column :
Column-I Column-II
(Gases X and Y (Tatio of times
taken of diffusion) taken)
(A) X = 100 ml of H2 at 1 bar, 25º C (P) 1 : 1225
Y = 200 ml of O2 at 2 bar, 25ºC
(B) X = 100 ml of O2 at 1 bar, 25ºC (Q) 1 : 0.7
Y = 200 ml of O3 at 2 bar, 25ºC
XtraEdge for IIT-JEE 56 FEBRUARY 2012