JEE MAIN - Chemistry (2022 - 27th July Morning Shift)

1

$$250 \mathrm{~g}$$ solution of $$\mathrm{D}$$-glucose in water contains $$10.8 \%$$ of carbon by weight. The molality of the solution is nearest to

(Given: Atomic Weights are, $$\mathrm{H}, 1 \,\mathrm{u} ; \mathrm{C}, 12 \,\mathrm{u} ; \mathrm{O}, 16 \,\mathrm{u}$$)

Answer
(B)
2.06
2

Given below are two statements.

Statement I: $$\mathrm{O}_{2}, \mathrm{Cu}^{2+}$$, and $$\mathrm{Fe}^{3+}$$ are weakly attracted by magnetic field and are magnetized in the same direction as magnetic field.

Statement II: $$\mathrm{NaCl}$$ and $$\mathrm{H}_{2} \mathrm{O}$$ are weakly magnetized in opposite direction to magnetic field.

In the light of the above statements, choose the most appropriate answer from the options given below.

Answer
(A)
Both Statement I and Statement II are correct.
3

Given below are two statements. One is labelled as Assertion A and the other is labelled as Reason R.

Assertion A: Energy of $$2 \mathrm{s}$$ orbital of hydrogen atom is greater than that of $$2 \mathrm{s}$$ orbital of lithium.

Reason R: Energies of the orbitals in the same subshell decrease with increase in the atomic number.

In the light of the above statements, choose the correct answer from the options given below.

Answer
(A)
Both A and R are true and R is the correct explanation of A.
4

Given below are two statements. One is labelled as Assertion A and the other is labelled as Reason R.

Assertion A : Activated charcoal adsorbs SO2 more efficiently than CH4.

Reason R : Gases with lower critical temperatures are readily adsorbed by activated charcoal.

In the light of the above statements, choose the correct answer from the options given below.

Answer
(C)
A is correct but R is not correct.
5
Boiling point of a $$2 \%$$ aqueous solution of a non-volatile solute A is equal to the boiling point of $$8 \%$$ aqueous solution of a non-volatile solute B. The relation between molecular weights of A and B is
Answer
(B)
$$\mathrm{M}_{\mathrm{B}}=4 \mathrm{M}_{\mathrm{A}}$$
6
The incorrect statement is
Answer
(D)
The first ionization enthalpy of Ga is higher than that of the d-block element with atomic number 30.
7

Given below are two statements.

Statement I : Iron (III) catalyst, acidified $$\mathrm{K}_{2} \mathrm{Cr}_{2} \mathrm{O}_{7}$$ and neutral $$\mathrm{KMnO}_{4}$$ have the ability to oxidise $$\mathrm{I}^{-}$$ to $$\mathrm{I}_{2}$$ independently.

Statement II : Manganate ion is paramagnetic in nature and involves $$\mathrm{p} \pi-\mathrm{p} \pi$$ bonding.

In the light of the above statements, choose the correct answer from the options given below.

Answer
(B)
Both Statement I and Statement II are false.
8
The total number of $$\mathrm{Mn}=\mathrm{O}$$ bonds in $$\mathrm{Mn}_{2} \mathrm{O}_{7}$$ is __________.
Answer
(C)
6
9

Given below are two statements: one is labelled as Assertion A and, the other is labelled as Reason R.

Assertion A: [6] Annulene, [8] Annulene and cis-[10] Annulene, are respectively aromatic, not-aromatic and aromatic.

JEE Main 2022 (Online) 27th July Morning Shift Chemistry - Basics of Organic Chemistry Question 105 English

Reason R: Planarity is one of the requirements of aromatic systems.

In the light of the above statements, choose the most appropriate answer from the options given below.

Answer
(D)
A is not correct but R is correct.
10

JEE Main 2022 (Online) 27th July Morning Shift Chemistry - Alcohols, Phenols and Ethers Question 65 English

In the above reaction product B is :

Answer
(A)
JEE Main 2022 (Online) 27th July Morning Shift Chemistry - Alcohols, Phenols and Ethers Question 65 English Option 1
11
A sugar 'X' dehydrates very slowly under acidic condition to give furfural which on further reaction with resorcinol gives the coloured product after sometime. Sugar 'X' is
Answer
(A)
Aldopentose
12

In Carius method of estimation of halogen, $$0.45 \mathrm{~g}$$ of an organic compound gave $$0.36 \mathrm{~g}$$ of $$\mathrm{AgBr}$$. Find out the percentage of bromine in the compound.

(Molar masses : $$\mathrm{AgBr}=188 \mathrm{~g} \mathrm{~mol}^{-1} ; \mathrm{Br}=80 \mathrm{~g} \mathrm{~mol}^{-1}$$)

Answer
(A)
34.04%
13

Match List I with List II.

List I List II
(A) Benzenesulphonyl chloride (I) Test for primary amines
(B) Hoffmann bromamide reaction (II) Anti Saytzeff
(C) Carbylamine reaction (III) Hinsberg reagent
(D) Hoffmann orientation (IV) Known reaction of Isocyanates.

Choose the correct answer from the options given below:

Answer
(C)
A-III, B-IV, C-I, D-II
14

$$20 \mathrm{~mL}$$ of $$0.02 \,\mathrm{M} \,\mathrm{K}_{2} \mathrm{Cr}_{2} \mathrm{O}_{7}$$ solution is used for the titration of $$10 \mathrm{~mL}$$ of $$\mathrm{Fe}^{2+}$$ solution in the acidic medium.

The molarity of $$\mathrm{Fe}^{2+}$$ solution is __________ $$\times \,10^{-2}\, \mathrm{M}$$. (Nearest Integer)

Answer
24
15

$$2 \mathrm{NO}+2 \mathrm{H}_{2} \rightarrow \mathrm{N}_{2}+2 \mathrm{H}_{2} \mathrm{O}$$

The above reaction has been studied at $$800^{\circ} \mathrm{C}$$. The related data are given in the table below

Reaction serial number Initial Pressure of $${H_2}/kPa$$ Initial Pressure of $$NO/kPa$$ Initial rate $$\left( {{{ - dp} \over {dt}}} \right)/(kPa/s)$$
1 65.6 40.0 0.135
2 65.6 20.1 0.033
3 38.6 65.6 0.214
4 19.2 65.6 0.106

The order of the reaction with respect to NO is ___________.

Answer
2
16

Amongst the following, the number of oxide(s) which are paramagnetic in nature is

$$\mathrm{Na}_{2} \mathrm{O}, \mathrm{KO}_{2}, \mathrm{NO}_{2}, \mathrm{~N}_{2} \mathrm{O}, \mathrm{ClO}_{2}, \mathrm{NO}, \mathrm{SO}_{2}, \mathrm{Cl}_{2} \mathrm{O}$$

Answer
4
17
The molar heat capacity for an ideal gas at constant pressure is $$20.785 \mathrm{~J} \mathrm{~K}^{-1} \mathrm{~mol}^{-1}$$. The change in internal energy is $$5000 \mathrm{~J}$$ upon heating it from $$300 \mathrm{~K}$$ to $$500 \mathrm{~K}$$. The number of moles of the gas at constant volume is ____________. [Nearest integer] (Given: $$\mathrm{R}=8.314 \mathrm{~J} \mathrm{~K}^{-1} \mathrm{~mol}^{-1}$$)
Answer
2
18

According to MO theory, number of species/ions from the following having identical bond order is ________.

$$\mathrm{CN}^{-}, \mathrm{NO}^{+}, \mathrm{O}_{2}, \mathrm{O}_{2}^{+}, \mathrm{O}_{2}^{2+}$$

Answer
3
19
At $$310 \mathrm{~K}$$, the solubility of $$\mathrm{CaF}_{2}$$ in water is $$2.34 \times 10^{-3} \mathrm{~g} / 100 \mathrm{~mL}$$. The solubility product of $$\mathrm{CaF}_{2}$$ is ____________ $$\times 10^{-8}(\mathrm{~mol} / \mathrm{L})^{3}$$. (Give molar mass : $$\mathrm{CaF}_{2}=78 \mathrm{~g} \mathrm{~mol}^{-1}$$)
Answer
0
20
The conductivity of a solution of complex with formula $$\mathrm{CoCl}_{3}\left(\mathrm{NH}_{3}\right)_{4}$$ corresponds to 1 : 1 electrolyte, then the primary valency of central metal ion is __________.
Answer
3
21
In the titration of $$\mathrm{KMnO}_{4}$$ and oxalic acid in acidic medium, the change in oxidation number of carbon at the end point is ___________.
Answer
1
22
Optical activity of an enantiomeric mixture is $$+12.6^{\circ}$$ and the specific rotation of $$(+)$$ isomer is $$+30^{\circ}$$. The optical purity is __________$$\%$$.
Answer
42
23

In the following reaction

JEE Main 2022 (Online) 27th July Morning Shift Chemistry - Alcohols, Phenols and Ethers Question 66 English

The $$\%$$ yield for reaction I is $$60 \%$$ and that of reaction II is $$50 \%$$. The overall yield of the complete reaction is __________ $$\%$$. [nearest integer]

Answer
30