JEE MAIN - Chemistry (2022 - 26th July Evening Shift)

1

Hemoglobin contains $$0.34 \%$$ of iron by mass. The number of Fe atoms in $$3.3 \mathrm{~g}$$ of hemoglobin is

(Given: Atomic mass of Fe is $$56 \,\mathrm{u}, \mathrm{N}_{\mathrm{A}}=6.022 \times 10^{23} \mathrm{~mol}^{-1}$$.)

Answer
(C)
$$1.21 \times 10^{20}$$
2

Arrange the following in increasing order of their covalent character.

A. $$\mathrm{CaF}_{2}$$

B. $$\mathrm{CaCl}_{2}$$

C. $$\mathrm{CaBr}_{2}$$

D. $$\mathrm{CaI}_{2}$$

Choose the correct answer from the options given below.

Answer
(B)
A < B < C < D
3

Class XII students were asked to prepare one litre of buffer solution of $$\mathrm{pH} \,8.26$$ by their Chemistry teacher: The amount of ammonium chloride to be dissolved by the student in $$0.2\, \mathrm{M}$$ ammonia solution to make one litre of the buffer is :

(Given: $$\mathrm{pK}_{\mathrm{b}}\left(\mathrm{NH}_{3}\right)=4.74$$

Molar mass of $$\mathrm{NH}_{3}=17 \mathrm{~g} \mathrm{~mol}^{-1}$$

Molar mass of $$\mathrm{NH}_{4} \mathrm{Cl}=53.5 \mathrm{~g} \mathrm{~mol}^{-1}$$ )

Answer
(C)
107.0 g
4

At $$30^{\circ} \mathrm{C}$$, the half life for the decomposition of $$\mathrm{AB}_{2}$$ is $$200 \mathrm{~s}$$ and is independent of the initial concentration of $$\mathrm{AB}_{2}$$. The time required for $$80 \%$$ of the $$\mathrm{AB}_{2}$$ to decompose is

Given: $$\log 2=0.30$$ $$\quad \log 3=0.48$$

Answer
(C)
467 s
5
The metal complex that is diamagnetic is (Atomic number: $$\mathrm{Fe}, 26 ; \mathrm{Cu}, 29)$$
Answer
(A)
$$\mathrm{K}_{3}\left[\mathrm{Cu}(\mathrm{CN})_{4}\right]$$
6
The correct decreasing order of priority of functional groups in naming an organic Question: compound as per IUPAC system of nomenclature is
Answer
(B)
$$\mathrm{SO}_{3} \mathrm{H}>-\mathrm{COCl}>-\mathrm{CONH}_{2}>-\mathrm{CN}$$
7
Which of the following is not an example of benzenoid compound?
Answer
A
B
8
Hydrolysis of which compound will give carbolic acid?
Answer
(B)
Benzenediazonium chloride
9

JEE Main 2022 (Online) 26th July Evening Shift Chemistry - Aldehydes, Ketones and Carboxylic Acids Question 83 English

Consider the above reaction and predict the major product.

Answer
(A)
JEE Main 2022 (Online) 26th July Evening Shift Chemistry - Aldehydes, Ketones and Carboxylic Acids Question 83 English Option 1
10

The correct sequential order of the reagents for the given reaction is

JEE Main 2022 (Online) 26th July Evening Shift Chemistry - Compounds Containing Nitrogen Question 83 English

Answer
(B)
$$\mathrm{HNO}_{2}, \mathrm{KI}, \mathrm{Fe} / \mathrm{H}^{+}, \mathrm{HNO}_{2}, \mathrm{H}_{2} \mathrm{O} /$$ warm
11
Animal starch is the other name of
Answer
(C)
glycogen.
12

Given below are two statements: one is labelled as Assertion $$\mathbf{A}$$ and the other is labelled as Reason $$\mathbf{R}$$.

Assertion A: Phenolphthalein is a $$\mathrm{pH}$$ dependent indicator, remains colourless in acidic solution and gives pink colour in basic medium.

Reason R: Phenolphthalein is a weak acid. It doesn't dissociate in basic medium.

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

Answer
(C)
A is true but R is false.
13
Consider an imaginary ion $${ }_{22}^{48} \mathrm{X}^{3-}$$. The nucleus contains '$$a$$'% more neutrons than the number of electrons in the ion. The value of 'a' is _______________. [nearest integer]
Answer
4
14

For the reaction

$$\mathrm{H}_{2} \mathrm{F}_{2}(\mathrm{~g}) \rightarrow \mathrm{H}_{2}(\mathrm{~g})+\mathrm{F}_{2}(\mathrm{~g})$$

$$\Delta U=-59.6 \mathrm{~kJ} \mathrm{~mol}^{-1}$$ at $$27^{\circ} \mathrm{C}$$.

The enthalpy change for the above reaction is ($$-$$) __________ $$\mathrm{kJ} \,\mathrm{mol}^{-1}$$ [nearest integer]

Given: $$\mathrm{R}=8.314 \mathrm{~J} \mathrm{~K}^{-1} \mathrm{~mol}^{-1}$$.

Answer
57
15
The elevation in boiling point for 1 molal solution of non-volatile solute A is $$3 \mathrm{~K}$$. The depression in freezing point for 2 molal solution of $$\mathrm{A}$$ in the same solvent is 6 $$K$$. The ratio of $$K_{b}$$ and $$K_{f}$$ i.e., $$K_{b} / K_{f}$$ is $$1: X$$. The value of $$X$$ is [nearest integer]
Answer
1
16

$$20 \mathrm{~mL}$$ of $$0.02\, \mathrm{M}$$ hypo solution is used for the titration of $$10 \mathrm{~mL}$$ of copper sulphate solution, in the presence of excess of KI using starch as an indicator. The molarity of $$\mathrm{Cu}^{2+}$$ is found to be ____________ $$\times 10^{-2} \,\mathrm{M}$$. [nearest integer]

Given : $$2 \,\mathrm{Cu}^{2+}+4 \,\mathrm{I}^{-} \rightarrow \mathrm{Cu}_{2} \mathrm{I}_{2}+\mathrm{I}_{2}$$

$$ \mathrm{I}_{2}+2 \mathrm{~S}_{2} \mathrm{O}_{3}^{2-} \rightarrow 2 \mathrm{I}^{-}+\mathrm{S}_{4} \mathrm{O}_{6}^{2-} $$

Answer
4
17
The spin-only magnetic moment value of the compound with strongest oxidizing ability among $$\mathrm{MnF}_{4}, \mathrm{MnF}_{3}$$ and $$\mathrm{MnF}_{2}$$ is ____________ B.M. [nearest integer]
Answer
5
18
Total number of isomers (including stereoisomers) obtained on monochlorination of methylcyclohexane is ___________.
Answer
12
19
A $$100 \mathrm{~mL}$$ solution of $$\mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{MgBr}$$ on treatment with methanol produces $$2.24 \mathrm{~mL}$$ of a gas at STP. The weight of gas produced is _____________ mg. [nearest integer]
Answer
3