JEE MAIN - Chemistry (2020 - 5th September Morning Slot)
1
The increasing order of the acidity of the $$\alpha $$-hydrogen of the following compounds is :
Answer
(D)
(D) < (C) < (A) < (B)
2
The increasing order of basicity of the following
compounds is :
Answer
(D)
(B) < (A) < (D) < (C)
3
A flask contains a mixture of compounds A and
B. Both compounds decompose by first-order
kinetics. The half-lives for A and B are 300 s
and 180 s, respectively. If the concentrations
of A and B are equal initially, the time required
for the concentration of A to be four times that
of B(in s) :
(Use ln 2 = 0.693)
Answer
(D)
900
4
The most appropriate reagent for conversion of
C2H5CN into CH3CH2CH2NH2 is
Answer
(D)
LiAlH4
5
The structure of PCl5
in the solid state is :
Answer
(B)
tetrahedral [PCl4]+ and octahedral [PCl6]–
6
The difference between the radii of 3rd and 4th orbits of Li2+ is R1
. The difference between the
radii of 3rd and 4th orbits of He+ is
$$\Delta $$R2
. Ratio $$\Delta $$R1 : $$\Delta $$R2 is :
Answer
(C)
2 : 3
7
Which of the following derivatives of alcohols
is unstable in an aqueous base?
Answer
(B)
8
The correct electronic configuration and spin-only magnetic moment (BM) of Gd3+ (Z = 64),
respectively, are :
Answer
(B)
[Xe]4f7 and 7.9
9
In the following reaction sequence the major
products A and B are :
Answer
(D)
10
Which of the following is not an essential
amino acid :
Answer
(D)
Tyrosine
11
Consider the following reaction:
N2O4(g) ⇌ 2NO2(g); $$\Delta $$Ho = +58 kJ
For each of the following cases (a, b), the direction in which the equilibrium shifts is :
(a) Temperature is decreased.
(b) Pressure is increased by adding N2
at constant T.
Answer
(B)
(a) towards reactant, (b) no change
12
The values of the crystal field stabilization
energies for a high spin d6 metal ion in
octahedral and tetrahedral fields, respectively,
are :
Answer
(C)
–0.4$$\Delta $$0
and –0.6$$\Delta $$t
13
An oxidation-reduction reaction in which 3 electrons are transferred has a $$\Delta $$Gº of 17.37 kJ mol–1 at
25 oC. The value of Eo cell (in V) is ______ × 10–2.
(1 F = 96,500 C mol–1)
Answer
-6
14
The total number of coordination sites in ethylenediaminetetraacetate (EDTA4–) is _____.
Answer
6
15
A soft drink was bottled with a partial pressure of CO2
of 3 bar over the liquid at room temperature.
The partial pressure of CO2
over the solution approaches a value of 30 bar when 44 g of CO2
is
dissolved in 1 kg of water at room temperature. The approximate pH of the soft drink is ______ $$ \times $$ 10–1.
(First dissociation constant of H2CO3
= 4.0 $$ \times $$ 10–7; log 2 = 0.3; density of the soft drink = 1 g mL–1)
.
Answer
37
16
The number of chiral carbon(s) present in
peptide, Ile-Arg-Pro, is _____.
Answer
4
17
The minimum number of moles of O2
required for complete combustion of 1 mole of propane and 2
moles of butane is _____.
Answer
18
18
The potential energy curve for the H2
molecule as a function of internuclear distance is :
Answer
(C)
19
In the sixth period, the orbitals that are filled are :
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