JEE Advance - Chemistry (2021 - Paper 2 Online)

1
The reaction sequence(s) that would lead to o-xylene as the major product is(are)
Answer
A
B
2
Correct option(s) for the following sequence of reactions is(are)

JEE Advanced 2021 Paper 2 Online Chemistry - Compounds Containing Nitrogen Question 21 English
Answer
C
D
3
For the following reaction,
$$2X + Y\buildrel k \over \longrightarrow P$$ the rate of reaction is $${{d[P]} \over {dt}} = k[X]$$. Two moles of X are mixed with one mole of Y to make 1.0 L of solution. At 50 s, 0.5 mole of Y is left in the reaction mixture. The correct statement(s) about the reaction is(are)

(Use : ln 2 = 0.693)
Answer
B
C
D
4
Some standard electrode potentials at 298 K are given below :

Pb2+ /Pb = $$- $$0.13 V

Ni2+ /Ni = $$-$$ 0.24 V

Cd2+ /Cd = $$-$$ 0.40 V

Fe2+ /Fe = $$-$$ 0.44 V

To a solution containing 0.001 M of X2+ and 0.1 M of Y2+, the metal rods X and Y are inserted (at 298 K) and connected by a conducting wire. This resulted in dissolution of X. The correct combination(s) of X and Y, respectively, is(are)

(Given : Gas constant, R = 8.314 J K$$-$$ mol$$-$$1, Faraday constant, F = 96500 C mol$$-$$1)
Answer
A
B
C
5
The pair(s) of complexes wherein both exhibit tetrahedral geometry is(are)

(Note : py = pyridine)

Given : Atomic numbers of Fe, Co, Ni and Cu are 26, 27, 28 and 29, respectively)
Answer
A
B
D
6
The correct statement(s) related to oxoacids of phosphorous is(are)
Answer
A
B
D
7
At 298 K, the limiting molar conductivity of a weak monobasic acid is 4 $$\times$$ 102 S cm2 mol$$-$$1. At 298 K, for an aqueous solution of the acid the degree of dissociation is $$\alpha$$ and the molar conductivity is y $$\times$$ 102 S cm2 mol$$-$$1. At 298 K, upon 20 times dilution with water, the molar conductivity of the solution becomes 3y $$\times$$ 102 S cm2 mol$$-$$1.

The value of $$\alpha$$ is __________.
Answer
0.22
8
At 298 K, the limiting molar conductivity of a weak monobasic acid is 4 $$\times$$ 102 S cm2 mol$$-$$1. At 298 K, for an aqueous solution of the acid the degree of dissociation is $$\alpha$$ and the molar conductivity is y $$\times$$ 102 S cm2 mol$$-$$1. At 298 K, upon 20 times dilution with water, the molar conductivity of the solution becomes 3y $$\times$$ 102 S cm2 mol$$-$$1.

The value of y is __________.
Answer
0.86
9
Reaction of x g of Sn with HCl quantitatively produced a salt. Entire amount of the salt reacted with y g of nitrobenzene in the presence of required amount of HCl to produce 1.29 g of an organic salt (quantitatively).

(Use Molar masses (in g mol$$-$$1) of H, C, N, O, Cl and Sn as 1, 12, 14, 16, 35 and 119, respectively).

The value of x is _________.
Answer
3.57
10
Reaction of x g of Sn with HCl quantitatively produced a salt. Entire amount of the salt reacted with y g of nitrobenzene in the presence of required amount of HCl to produce 1.29 g of an organic salt (quantitatively).

(Use Molar masses (in g mol$$-$$1) of H, C, N, O, Cl and Sn as 1, 12, 14, 16, 35 and 119, respectively).

The value of y is _________.
Answer
1.23
11
A sample (5.6 g) containing iron is completely dissolved in cold dilute HCl to prepare a 250 mL of solution. Titration of 25.0 mL of this solution requires 12.5 mL of 0.03 M KMnO4 solution to reach the end point. Number of moles of Fe2+ present in 250 mL solution is x $$\times$$ 10$$-$$2 (consider complete dissolution of FeCl2). The amount of iron present in the sample is y% by weight.

(Assume : KMnO4 reacts only with Fe2+ in the solution

Use : Molar mass of iron as 56 g mol$$-$$1)

The value of x is ______.
Answer
1.875
Or +1 more
12
A sample (5.6 g) containing iron is completely dissolved in cold dilute HCl to prepare a 250 mL of solution. Titration of 25.0 mL of this solution requires 12.5 mL of 0.03 M KMnO4 solution to reach the end point. Number of moles of Fe2+ present in 250 mL solution is x $$\times$$ 10$$-$$2 (consider complete dissolution of FeCl2). The amount of iron present in the sample is y% by weight.

(Assume : KMnO4 reacts only with Fe2+ in the solution

Use : Molar mass of iron as 56 g mol$$-$$1)

The value of y is ______.
Answer
18.75
13
Correct match of the C-H bonds (shown in bold) in Column J with their BDE in Column K is

Column J
Molecule
Column K
BDE (kcal $$mo{l^{ - 1}}$$)
(P) H-CH($$C{H_3}$$)$$_2$$ (i) 132
(Q) H-CH$$_2$$Ph (ii) 110
(R) H-CH=CH$$_2$$ (iii) 95
(S) H-C $$ \equiv $$ CH (iv) 88
Answer
(A)
P - iii, Q - iv, R - ii, S - i
14
For the following reaction

CH4(g) + Cl2(g) $$\buildrel {light} \over \longrightarrow $$ CH3Cl(g) + HCl (g)

the correct statement is
Answer
(D)
The reaction is exothermic with $$\Delta$$H$$^\circ$$ = $$-$$25 kcal mol$$-$$1.
15
Precipitate X is
Answer
(C)
K2Fe[Fe(CN)6]
16
Among the following, the brown ring is due to the formation of
Answer
(D)
[Fe(NO)(H2O)5]2+
17
One mole of an ideal gas at 900 K, undergoes two reversible processes, I followed by II, as shown below. If the work done by the gas in the two processes are same, the value of $$\ln {{{V_3}} \over {{V_2}}}$$ is _________.

JEE Advanced 2021 Paper 2 Online Chemistry - Thermodynamics Question 17 English
(U : internal energy, S : entropy, p : pressure, V : volume, R : gas constant)

(Given : molar heat capacity at constant volume, CV,m of the gas is $${5 \over 2}$$R)
Answer
10
18
Consider a helium (He) atom that absorbs a photon of wavelength 330 nm. The change in the velocity (in cm s$$-$$1) of He atom after the photon absorption is __________.

(Assume : Momentum is conserved when photon is absorbed.

Use : Planck constant = 6.6 $$\times$$ 10$$-$$34 J s, Avogadro number = 6 $$\times$$ 1023 mol$$-$$1, Molar mass of He = 4 g mol$$-$$1)
Answer
30
19
Ozonolysis of ClO2 produces an oxide of chlorine. The average oxidation state of chlorine in this oxide is __________.
Answer
6