
SECTION-A
61. Given below are two statements : one is labelled as
Assertion A and the other is labelled as Reason R:
Assertion A: The first ionisation enthalpy decreases
across a period.
Reason R: The increasing nuclear charge outweighs
the shielding across the period.
In the light of the above statements, choose the
most appropriate from the options given below:
(1) Both A and R are true and R is the correct
explanation of A
(2) A is true but R is false
(3) A is false but R is true
(4) Both A and R are true but R is NOT the
correct explanation of A
Ans. (3)
Sol. First ionisation energy increases along the period.
Along the period Z increases which outweighs the
shielding effect
62. Match List I with List II
LIST-I LIST-II
(Substances) (Element Present)
A.Ziegler catalyst I.Rhodium
B.Blood Pigment II. Cobalt
C.Wilkinson catalyst III.Iron
D.Vitamin B12 IV.Titanium
Choose the correct answer from the options given
below:
(1) A-II, B-IV, C-I, D-III
(2) A-II, B-III, C-IV, D-I
(3) A-III, B-II, C-IV, D-I
(4) A-IV, B-III, C-I, D-II
Ans. (4)
Sol. Ziegler catalyst Titanium
Blood pigment Iron
Wilkinson catalyst Rhodium
Vitamin B12Cobalt
63. In chromyl chloride test for confirmation of Cl–
ion, a yellow solution is obtained. Acidification of
the solution and addition of amyl alcohol and 10%
H2O2 turns organic layer blue indicating formation
of chromium pentoxide. The oxidation state of
chromium in that is
(1)+6 (2)+5
(3)+10 (4)+3
Ans. (1)
Sol.
Basic medium 2
2 2 7 2 4 2 2 4
yellow solution
Cl K Cr O H SO CrO Cl CrO Cl
22
1.Acidification
2. Amyl alcohol
2
45
3.10% H O
yellow solution blue compound
CrO CrO
64. The difference in energy between the actual
structure and the lowest energy resonance structure
for the given compound is
(1) electromeric energy
(2) resonance energy
(3) ionization energy
(4) hyperconjugation energy
Ans. (2)
Sol. The difference in energy between the actual structure
and the lowest energy resonance structure for the
given compound is known as resonance energy.
65. Given below are two statements :
Statement I : The electronegativity of group 14
elements from Si to Pb gradually decreases.
Statement II : Group 14 contains non-metallic,
metallic, as well as metalloid elements.
In the light of the above statements, choose the
most appropriate from the options given below :
(1) Statement I is false but Statement II is true
(2) Statement I is true but Statement II is false
(3) Both Statement I and Statement II are true
(4) Both Statement I and Statement II are false
Ans. (1)