JEE MAIN - Chemistry (2020 - 2nd September Evening Slot)
1
For the disproportionation reaction
2Cu+(aq) ⇌ Cu(s) + Cu2+(aq) at 298 K. ln K
(where K is the equilibrium constant) is
___________ × 10–1.
Given :
($$E_{C{u^{2 + }}/C{u^ + }}^0 = 0.16V$$
$$E_{C{u^ + }/Cu}^0 = 0.52V$$
$${{RT} \over F} = 0.025$$)
Answer
144
2
The ratio of the mass percentages of ‘C & H’
and ‘C & O’ of a saturated acyclic organic
compound ‘X’ are 4 : 1 and 3 : 4 respectively.
Then, the moles of oxygen gas required for
complete combustion of two moles of organic
compound ‘X’ is ________.
Answer
5
3
The work function of sodium metal is
4.41 $$ \times $$ 10–19 J. If photons of wavelength 300 nm
are incident on the metal, the kinetic energy of
the ejected electrons will be (h = 6.63 $$ \times $$ 10–34 J s;
c = 3 $$ \times $$ 108 m/s) ________ × 10–21 J.
Answer
222
4
The oxidation states of transition metal atoms
in K2Cr2O7, KMnO4 and K2FeO4, respectively,
are x, y and z. The sum of x, y and z is _______.
Answer
19
5
The heat of combustion of ethanol into carbon
dioxide and water is – 327 kcal at constant
pressure. The heat evolved (in cal) at constant
volume and 27oC (if all gases behave ideally) is
(R = 2 cal mol–1 K–1) ________.
Answer
326400
6
The ratio of the mass percentages of ‘C & H’
and ‘C & O’ of a saturated acyclic organic
compound ‘X’ are 4 : 1 and 3 : 4 respectively.
Then, the moles of oxygen gas required for
complete combustion of two moles of organic
compound ‘X’ is ________.
Answer
5
7
For the disproportionation reaction
2Cu+(aq) ⇌ Cu(s) + Cu2+(aq) at 298 K. ln K
(where K is the equilibrium constant) is
___________ × 10–1.
Given :
($$E_{C{u^{2 + }}/C{u^ + }}^0 = 0.16V$$
$$E_{C{u^ + }/Cu}^0 = 0.52V$$
$${{RT} \over F} = 0.025$$)
Answer
144
8
The oxidation states of transition metal atoms
in K2Cr2O7, KMnO4 and K2FeO4, respectively,
are x, y and z. The sum of x, y and z is _______.
Answer
19
9
An organic compound ‘A’ (C9H10O) when
treated with conc. HI undergoes cleavage to
yield compounds ‘B’ and ‘C’. ‘B’ gives yellow
precipitate with AgNO3 where as ‘C’
tautomerizes to ‘D’. ‘D’ gives positive iodoform
test. ‘A’ could be
Answer
(C)
10
Two compounds A and B with same molecular
formula (C3H6O) undergo Grignard’s reaction
with methylmagnesium bromide to give
products C and D. Products C and D show
following chemical tests.
C and D respectively are :
Answer
(D)
11
The molecular geometry of SF6 is octahedral.
What is the geometry of SF4 (including lone
pair(s) of electrons, if any)?
Answer
(B)
Trigonal bipyramidal
12
The results given in the below table were
obtained during kinetic studies of the following
reaction
2A + B $$ \to $$ C + D
X and Y in the given table are respectively :
Answer
(A)
0.3, 0.4
13
The results given in the below table were
obtained during kinetic studies of the following
reaction
2A + B $$ \to $$ C + D
X and Y in the given table are respectively :
Answer
(A)
0.3, 0.4
14
Match the type of interaction in column A with
the distance dependence of their interaction
energy in column B
A
B
(i) ion-ion
(a) $${1 \over r}$$
(ii) dipole-dipole
(b) $${1 \over {{r^2}}}$$
(iii) London dispersion
(c) $${1 \over {{r^3}}}$$
(d) $${1 \over {{r^6}}}$$
Answer
(D)
(I)-(a), (II)-(c), (III)-(d)
15
The size of a raw mango shrinks to a much
smaller size when kept in a concentrated salt
solution. Which one of the following processes
can explain this?
Answer
(A)
Osmosis
16
The one that is not expected to show isomerism
is :
Answer
(D)
[Ni(NH3)2Cl2]
17
If you spill a chemical toilet cleaning liquid on
your hand, your first aid would be
Answer
(B)
aqueous NaHCO3
18
The number of subshells associated with n = 4
and m = –2 quantum numbers is
Answer
(B)
2
19
Consider the reaction sequence given below:
Which of the following statements is true?
Answer
(A)
Changing the concentration of base will
have no effect on reaction (1)
20
Arrange the following labelled hydrogens in
decreasing order of acidity :
Answer
(A)
b > c > d > a
21
Consider the reaction sequence given below:
Which of the following statements is true?
Answer
(A)
Changing the concentration of base will
have no effect on reaction (1)
22
Arrange the following labelled hydrogens in
decreasing order of acidity :
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_2nd_September_Evening_Slot_en_19_2.png)
_2nd_September_Evening_Slot_en_20_1.png)
_2nd_September_Evening_Slot_en_21_2.png)
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