JEE MAIN - Chemistry (2020 - 3rd September Evening Slot)
1
The d-electron configuration of [Ru(en)3
]Cl2 and [Fe(H2O)6]Cl2
, respectively are :
Answer
(C)
$$t_{2g}^6e_g^0$$ and $$t_{2g}^4e_g^2$$
2
Consider the following reaction :
The product 'P' gives positive ceric ammonium nitrate test. This is because of the presence of
which of these –OH group(s)?
Answer
(A)
(b) only
3
For the reaction 2A + 3B +
$${3 \over 2}$$C
$$ \to $$ 3P, which
statement is correct ?
Complex A has a composition of H12O6Cl3Cr. If the complex on treatment with conc.H2SO4
loses
13.5% of its original mass, the correct molecular formula of A is :
[Given: atomic mass of Cr = 52 amu and Cl = 35 amu]
Answer
(B)
[Cr(H2O)4Cl2]Cl.2H2O
5
Consider the following molecules and
statements related to them :
(a) (B) is more likely to be crystalline than (A)
(b) (B) has higher boiling point than (A)
(c) (B) dissolves more readily than (A) in water
Identify the correct option from below :
Answer
(B)
(a), (b) and (c) are true
6
The compound A in the following reaction is :
Answer
(D)
7
The incorrect statement is :
Answer
(C)
Manganate and permanganate ions are
paramagnetic
8
The increasing order of the reactivity of the
following compound in nucleophilic addition
reaction is :
Propanal, Benzaldehyde, Propanone, Butanone
Answer
(A)
Butanone < Propanone < Benzaldehyde <
Propanal
9
The decreasing order of reactivity of the
following compounds towards nucleophilic
substitution (SN2) is :
Answer
(D)
(III) > (II) > (IV) > (I)
10
The major product in the following reaction is :
Answer
(A)
11
100 mL of 0.1 M HCl is taken in a beaker and
to it 100 mL of 0.1 M NaOH is added in steps
of 2 mL and the pH is continuously measured.
Which of the following graphs correctly depicts
the change in pH?
Answer
(C)
12
Three isomers A, B and C (mol. formula C8H11N) give the following results :
R has lower boiling point than S
A, B and C, respectively are :
Answer
(D)
13
The five successive ionization enthalpies of an
element are 800, 2427, 3658, 25024 and 32824
kJ mol–1. The number of valence electrons in
the element is :
Answer
(B)
3
14
Consider the hypothetical situation where the
azimuthal quantum number,
$$l$$, takes values 0,
1, 2, ....., n + 1, where n is the principal
quantum number. Then, the element with
atomic number :
Answer
(A)
13 has a half-filled valence subshell
15
Among the statements (I – IV), the correct ones
are:
(I) Be has smaller atomic radius compared to
Mg.
(II) Be has higher ionization enthalpy than Al.
(III) Charge/radius ratio of Be is greater than
that of Al.
(IV) Both Be and Al form mainly covalent
compounds.
Answer
(A)
(I), (II) and (IV)
16
The strengths of 5.6 volume hydrogen peroxide
(of density 1 g/mL) in terms of mass percentage
and molarity (M), respectively, are:
(Take molar mass of hydrogen peroxide as
34 g/mol)
Answer
(D)
1.7 and 0.5
17
The number of
groups present in a tripeptide Asp–Glu–Lys is ____.
Answer
5
18
6.023 $$ \times $$ 1022 molecules are present in 10 g of a substance 'x'. The molarity of a solution containing
5 g of substance 'x' in 2 L solution is _____ × 10-3
Answer
25
19
If 250 cm3
of an aqueous solution containing 0.73 g of a protein A is isotonic with one litre of
another aqueous solution containing 1.65 g of a protein B, at 298 K, the ratio of the molecular
masses of A and B is ______ × 10–2 (to the nearest integer).
Answer
177
20
The volume (in mL) of 0.1 N NaOH required to neutralise 10 mL of 0.1 N phosphinic acid is ___________.
Answer
10
21
An acidic solution of dichromate is electrolyzed
for 8 minutes using 2A current. As per the
following equation
Cr2O72-
+ 14H+ + 6e– $$ \to $$ 2Cr3+ + 7H2O
The amount of Cr3+ obtained was 0.104 g. The
efficiency of the process(in%) is
(Take : F = 96000 C, At. mass of chromium = 52)
______.
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groups present in a tripeptide Asp–Glu–Lys is ____.