JEE MAIN - Chemistry (2020 - 8th January Evening Slot)
1
The increasing order of the atomic radii of the
following elements is :-
(a) C (b) O (c) F (d) Cl
(e) Br
Answer
(B)
(c) < (b) < (a) < (d) < (e)
2
Consider the following plots of rate constant
versus $${1 \over T}$$ for four different reactions. Which
of the following orders is correct for the
activation energies of these reactions?
Answer
(A)
Ec > Ea > Ed > Eb
3
Kjeldahl's method cannot be used to estimate
nitrogen for which of the following
compounds?
Answer
(C)
C6H5NO2
4
Among the compounds A and B with
molecular formula C9H18O3 , A is having higher
boiling point the B. The possible structures of
A and B are :
Answer
(D)
5
An unsaturated hydrocarbon X absorbs two
hydrogen molecules on catalytic hydrogenation and also gives following reaction :
B(3 - oxo - hexanedicarboxylic acid) X will be :-
Answer
(C)
6
For the following Assertion and Reason, the
correct option is :
Assertion : The pH of water increases with
increase in temperature.
Reason : The dissociation of water into H+ and
OH– is an exothermic reaction.
Answer
(A)
Both assertion and reason are false.
7
The radius of the second Bohr orbit, in terms
of the Bohr radius, a0, in Li2+ is :
Answer
(D)
$${{4{a_0}} \over 3}$$
8
Complexes (ML5) of metals Ni and Fe have
ideal square pyramidal and trigonal
bipyramidal grometries, respectively. The sum
of the 90°, 120° and 180° L-M-L angles in the
two complexes is ________.
Answer
20
9
At constant volume, 4 mol of an ideal gas when
heated from 300 K to 500K changes its internal
energy by 5000 J. The molar heat capacity at
constant volume is _______.
Answer
6.25
10
In the following sequence of reactions the
maximum number of atoms present in
molecule 'C' in one plane is _________.
(A is a lowest molecular weight alkyne)
Answer
13
11
For an electrochemical cell
Sn(s) | Sn2+ (aq,1M)||Pb2+ (aq,1M)|Pb(s)
the ratio $${{\left[ {S{n^{2 + }}} \right]} \over {\left[ {P{b^{2 + }}} \right]}}$$ when this cell attains
equilibrium is _________.
The correct order of the calculated spin-only
magnetic moments of complexs (A) to (D) is:
(A) Ni(CO)4
(B) [Ni(H2O)6]Cl2
(C) Na2[Ni(CN)4]
(D) PdCl2(PPh3)2
Answer
(C)
(A) $$ \approx $$ (C) $$ \approx $$ (D) < (B)
13
Hydrogen has three isotopes (A), (B) and (C).
If the number of neutron(s) in (A), (B) and (C)
respectively, are (x), (y) and (z), the sum of (x),
(y) an (z) is :
Answer
(A)
3
14
The major product in the following reaction is:
Answer
(D)
15
Among (a) – (d) the complexes that can display
geometrical isomerism are :
(a) [Pt(NH3)3Cl]+
(b) [Pt(NH3)Cl5]–
(c) [Pt(NH3)2Cl(NO2)]
(d) [Pt(NH3)4ClBr]2+
Answer
(B)
(c) and (d)
16
Two monomers in maltose are :
Answer
(C)
$$\alpha $$-D-glucose and $$\alpha $$-D-glucose
17
Arrange the following bonds according to their
average bond energies in descending order :
C–Cl, C–Br, C–F, C–I
Answer
(D)
C–F > C–Cl > C–Br > C–I
18
A metal (A) on heating in nitrogen gas gives
compound B. B on treatment with H2O gives
a colourless gas which when passed through
CuSO4 solution gives a dark blue-violet
coloured solution. A and B respectively, are :
Answer
(C)
Mg and Mg3N2
19
The major product [B] in the following
sequence of reactions is :-
_8th_January_Evening_Slot_en_2_1.png)
_8th_January_Evening_Slot_en_4_4.png)
_8th_January_Evening_Slot_en_5_1.png)
B(3 - oxo - hexanedicarboxylic acid) X will be :-_8th_January_Evening_Slot_en_5_4.png)
_8th_January_Evening_Slot_en_10_1.png)
(A is a lowest molecular weight alkyne)_8th_January_Evening_Slot_en_14_1.png)
_8th_January_Evening_Slot_en_14_5.png)
_8th_January_Evening_Slot_en_19_1.png)
_8th_January_Evening_Slot_en_19_4.png)
