JEE MAIN - Chemistry (2021 - 27th August Morning Shift)

1
In the following sequence of reactions, the final product D is :

Answer
(D)
JEE Main 2021 (Online) 27th August Morning Shift Chemistry - Alcohols, Phenols and Ethers Question 89 English Option 4
2
The structure of the starting compound P used in the reaction given below is :

JEE Main 2021 (Online) 27th August Morning Shift Chemistry - Aldehydes, Ketones and Carboxylic Acids Question 114 English
Answer
(A)
JEE Main 2021 (Online) 27th August Morning Shift Chemistry - Aldehydes, Ketones and Carboxylic Acids Question 114 English Option 1
3
Match List - I with List - II :

JEE Main 2021 (Online) 27th August Morning Shift Chemistry - Chemical Bonding & Molecular Structure Question 128 English
Choose the most appropriate answer from the options given below :
Answer
(D)
(a)-(iv), (b)-(ii), (c)-(i), (d)-(iii)
4
Match items of List-I with those of List-II :

List - I
(Property)
List - II
(Example)
(a) Diamagnetism (i) MnO
(b) Ferrimagnetism (ii) $${O_2}$$
(c) Paramagnetism (iii) NaCl
(d) Antiferromagnetism (iv) $$F{e_3}{O_4}$$


Choose the most appropriate answer from the options given below :
Answer
(C)
(a)-(iii), (b)-(iv), (c)-(ii), (d)-(i)
5
The major product of the following reaction is :

Answer
(C)
JEE Main 2021 (Online) 27th August Morning Shift Chemistry - Compounds Containing Nitrogen Question 111 English Option 3
6
Which of the following is not a correct statement for primary aliphatic amines?
Answer
(A)
The intermolecular association in primary amines is less than the intermolecular association in secondary amines.
7
Acidic ferric chloride solution on treatment with excess of potassium ferrocyanide gives a Prussian blue coloured colloidal species. It is :
Answer
(A)
Fe4[Fe(CN)6]3
8
The nature of oxides V2O3 and CrO is indexed as 'X' and 'Y' type respectively. The correct set of X and Y is :
Answer
(D)
X = basic Y = basic
9
Out of following isomeric forms of uracil, which one is present in RNA?
Answer
(D)
JEE Main 2021 (Online) 27th August Morning Shift Chemistry - Biomolecules Question 86 English Option 4
10
Given below are two statements : one is labelled as Assertion (A) and the other is labelled as Reason (R).

Assertion (A) : Synthesis of ethyl phenyl ether may be achieved by Williamson synthesis.

Reason (R) : Reaction of bromobenzene with sodium ethoxide yields ethyl phenyl ether.

In the light of the above statements, choose the most appropriate answer from the options given below :
Answer
(B)
(A) is correct but (R) is not correct
11
In the following sequence of reactions the P is :

JEE Main 2021 (Online) 27th August Morning Shift Chemistry - Haloalkanes and Haloarenes Question 78 English
Answer
(A)
JEE Main 2021 (Online) 27th August Morning Shift Chemistry - Haloalkanes and Haloarenes Question 78 English Option 1
12
In polythionic acid, H2SxO6 (x = 3 to 5) the oxidation state(s) of sulphur is/are :
Answer
(D)
0 and + 5 only
13
In Carius method for estimation of halogens, 0.2 g of an organic compound gave 0.188 g of AgBr. The percentage of bromine in the compound is ______________. (Nearest integer)

[Atomic mass : Ag = 108, Br = 80]
Answer
40
14
The reaction that occurs in a breath analyser, a device used to determine the alcohol level in a person's blood stream is

$$2{K_2}C{r_2}{O_7} + 8{H_2}S{O_4} + 3{C_2}{H_6}O \to 2C{r_2}{(S{O_4})_3} + 3{C_2}{H_4}{O_2} + 2{K_2}S{O_4} + 11{H_2}O$$

If the rate of appearance of Cr2(SO4)3 is 2.67 mol min$$-$$1 at a particular time, the rate of disappearance of C2H6O at the same time is _____________ mol min$$-$$1. (Nearest integer)
Answer
4
15
The kinetic energy of an electron in the second Bohr orbit of a hydrogen atom is equal to $${{{h^2}} \over {xma_0^2}}$$. The value of 10x is ___________. (a0 is radius of Bohr's orbit) (Nearest integer) [Given : $$\pi$$ = 3.14]
Answer
3155
16
1 kg of 0.75 molal aqueous solution of sucrose can be cooled up to $$-$$4$$^\circ$$C before freezing. The amount of ice (in g) that will be separated out is __________. (Nearest integer)

[Given : Kf(H2O) = 1.86 K kg mol$$-$$1]
Answer
518
17
1 mol of an octahedral metal complex with formula MCl3 . 2L on reaction with excess of AgNO3 gives 1 mol of AgCl. The denticity of Ligand L is ____________. (Integer answer)
Answer
2
18
The number of moles of CuO, that will be utilized in Dumas method for estimation nitrogen in a sample of 57.5 g of N, N-dimethylaminopentane is _____________ $$\times$$ 10$$-$$2. (Nearest integer)
Answer
1125
19
The number of f electrons in the ground state electronic configuration of Np (Z = 93) is ___________. (Nearest integer)
Answer
18
20
200 mL of 0.2 M HCl is mixed with 300 mL of 0.1 M NaOH. The molar heat of neutralization of this reaction is $$-$$57.1 kJ. The increase in temperature in $$^\circ$$C of the system on mixing is x $$\times$$ 10$$-$$2. The value of x is ___________. (Nearest integer)

[Given : Specific heat of water = 4.18 J g$$-$$1 K$$-$$1, Density of water = 1.00 g cm$$-$$3]

[Assume no volume change on mixing)
Answer
82
21
The number of moles of NH3, that must be added to 2L of 0.80 M AgNO3 in order to reduce the concentration of Ag+ ions to 5.0 $$\times$$ 10$$-$$8 M (Kformation for [Ag(NH3)2]+ = 1.0 $$\times$$ 108) is ____________. (Nearest integer)

[Assume no volume change on adding NH3]
Answer
4
22
When 10 mL of an aqueous solution of KMnO4 was titrated in acidic medium, equal volume of 0.1 M of an aqueous solution of ferrous sulphate was required for complete discharge of colour. The strength of KMnO4 in grams per litre is __________ $$\times$$ 10$$-$$2. (Nearest integer)

[Atomic mass of K = 39, Mn = 55, O = 16]
Answer
316