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1

JEE Main 2021 (Online) 27th August Morning Shift

MCQ (Single Correct Answer)
Match items of List-I with those of List-II :

List - I
(Property)
List - II
(Example)
(a) Diamagnetism (i) MnO
(b) Ferrimagnetism (ii) $${O_2}$$
(c) Paramagnetism (iii) NaCl
(d) Antiferromagnetism (iv) $$F{e_3}{O_4}$$


Choose the most appropriate answer from the options given below :
A
(a)-(ii), (b)-(i), (c)-(iii), (d)-(iv)
B
(a)-(i), (b)-(iii), (c)-(iv), (d)-(ii)
C
(a)-(iii), (b)-(iv), (c)-(ii), (d)-(i)
D
(a)-(iv), (b)-(ii), (c)-(i), (d)-(iii)

Explanation

A. NaCl is diamagnetic because all electrons are paired in Na+ and in Cl . So, it shows diamagnetism.

B. Fe3O4 is ferrimagnetic because of the presence of the unequal alignment of magnetic moment in opposite direction.

C. O2 molecule has two unpaired electrons. So, it is paramagnetic.

D. In MnO, the orientation of the electrons of Mn and O is such that they cancel their effects, hence it is antiferromagnetic.

2

JEE Main 2021 (Online) 27th August Morning Shift

MCQ (Single Correct Answer)
Match List - I with List - II :


Choose the most appropriate answer from the options given below :
A
(a)-(iv), (b)-(i), (c)-(ii), (d)-(iii)
B
(a)-(iii), (b)-(iv), (c)-(ii), (d)-(i)
C
(a)-(iii), (b)-(ii), (c)-(iv), (d)-(i)
D
(a)-(iv), (b)-(ii), (c)-(i), (d)-(iii)

Explanation

Species
(Number of lone pairs of

electrons on the central atom)
$$Xe{F_2}$$
$$Xe{O_2}{F_2}$$
$$Xe{O_3}{F_2}$$
$$Xe{F_4}$$
3

JEE Main 2021 (Online) 26th August Evening Shift

MCQ (Single Correct Answer)
The bond order and magnetic behaviour of $$O_2^ - $$ ion are respectively :
A
1.5 and paramagnetic
B
1.5 and diamagnetic
C
2 and diamagnetic
D
1 and paramagnetic

Explanation

$$O_2^ - = {({\sigma _{1s}})^2}{(\sigma _{1s}^*)^2}{({\sigma _{2s}})^2}{(\sigma _{2s}^*)^2}{({\sigma _{2{p_z}}})^2}$$$$\left( {\pi _{2{p_x}}^2 = \pi _{2{p_y}}^2} \right)\left( {\pi _{2{p_x}}^{*2} = \pi _{2{p_y}}^{*1}} \right)$$

Bond order = $${{10 - 7} \over 2} = 1.5$$

and paramagnetic.
4

JEE Main 2021 (Online) 25th July Evening Shift

MCQ (Single Correct Answer)
Identify the species having one $$\pi$$-bond and maximum number of canonical forms from the following :
A
SO3
B
O2
C
SO2
D
CO$$_3^{2 - }$$

Explanation

Among SO3, O2, SO2 and CO$$_3^{2 - }$$, only O2 and CO$$_3^{2 - }$$ has only one $$\pi$$-bond.

Questions Asked from Chemical Bonding & Molecular Structure

On those following papers in MCQ (Single Correct Answer)
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JEE Main 2021 (Online) 1st September Evening Shift (1)
JEE Main 2021 (Online) 27th August Morning Shift (2)
JEE Main 2021 (Online) 26th August Evening Shift (1)
JEE Main 2021 (Online) 25th July Evening Shift (2)
JEE Main 2021 (Online) 22th July Evening Shift (1)
JEE Main 2021 (Online) 20th July Evening Shift (1)
JEE Main 2021 (Online) 20th July Morning Shift (1)
JEE Main 2021 (Online) 18th March Evening Shift (1)
JEE Main 2021 (Online) 17th March Evening Shift (1)
JEE Main 2021 (Online) 17th March Morning Shift (1)
JEE Main 2021 (Online) 16th March Morning Shift (1)
JEE Main 2021 (Online) 26th February Evening Shift (1)
JEE Main 2021 (Online) 26th February Morning Shift (1)
JEE Main 2021 (Online) 25th February Evening Shift (1)
JEE Main 2021 (Online) 25th February Morning Shift (1)
JEE Main 2021 (Online) 24th February Evening Shift (2)
JEE Main 2021 (Online) 24th February Morning Shift (1)
JEE Main 2020 (Online) 5th September Evening Slot (1)
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JEE Main 2020 (Online) 4th September Evening Slot (1)
JEE Main 2020 (Online) 4th September Morning Slot (1)
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