JEE MAIN - Chemistry (2020 - 6th September Morning Slot)

1
The number of Cl = O bonds in perchloric acid is, "________".
Answer
3
2
The elevation of boiling point of 0.10 m aqueous CrCl3.xNH3 solution is two times that of 0.05 m aqueous CaCl2 solution. The value of x is ______.

[Assume 100% ionisation of the complex and CaCl2, coordination number of Cr as 6, and that all NH3 molecules are present inside the coordination sphere]
Answer
5
3
Potassium chlorate is prepared by the electrolysis of KCl in basic solution

6OH- + Cl- $$ \to $$ ClO3- + 3H2O + 6e-

If only 60% of the current is utilized in the reaction, the time (rounded to the nearest hour) required to produce 10 g of KClO3 using a current of 2 A is_________.

(Given : F = 96,500 C mol–1; molar mass of KCIO3 = 122 g mol–1)
Answer
11
4
In an estimation of bromine by Carius method, 1.6 g of an organic compound gave 1.88 g of AgBr. The mass percentage of bromine in the compound is _______.
(Atomic mass, Ag = 108, Br = 80 g mol–1)
Answer
50
5
The set that contains atomic numbers of only transition elements, is :
Answer
(D)
21, 25, 42, 72
6
Consider the following reactions JEE Main 2020 (Online) 6th September Morning Slot Chemistry - Aldehydes, Ketones and Carboxylic Acids Question 150 English
'A' is :
Answer
(B)
JEE Main 2020 (Online) 6th September Morning Slot Chemistry - Aldehydes, Ketones and Carboxylic Acids Question 150 English Option 2
7
The variation of equilibrium constant with temperature is given below :

Temperature Equilibrium Constant
T1 = 25oC K1 = 10
T2 = 100oC K2 = 100

The values of $$\Delta $$Ho, $$\Delta $$Go at
T1 and $$\Delta $$Go at T2 (in kJ mol–1) respectively, are close to :
[Use R = 8.314 J K–1 mol–1]
Answer
(A)
28.4, –5.71 and –14.29
8
Consider the following reactions

A $$ \to $$ P1 ; B $$ \to $$ P2 ; C $$ \to $$ P3 ; D $$ \to $$ P4,

The order of the above reactions are a, b, c, and d, respectively. The following graph is obtained when log[rate] vs. log[conc.] are plotted JEE Main 2020 (Online) 6th September Morning Slot Chemistry - Chemical Kinetics and Nuclear Chemistry Question 108 English
Among the following, the correct sequence for the order of the reactions is :
Answer
(A)
d > b > a > c
9
The correct statement with respect to dinitrogen is :
Answer
(B)
it can be used as an inert diluent for reactive chemicals
10
The major product obtained from the following reaction is :
Answer
(C)
JEE Main 2020 (Online) 6th September Morning Slot Chemistry - Hydrocarbons Question 90 English Option 3
11
Which of the following compounds shows geometrical isomerism?
Answer
(D)
4-methylpent-2-ene
12
The lanthanoid that does NOT show +4 oxidation state is :
Answer
(D)
Eu
13
The major products of the following reaction are : JEE Main 2020 (Online) 6th September Morning Slot Chemistry - Aldehydes, Ketones and Carboxylic Acids Question 151 English
Answer
(D)
JEE Main 2020 (Online) 6th September Morning Slot Chemistry - Aldehydes, Ketones and Carboxylic Acids Question 151 English Option 4
14
The major product of the following reaction is : JEE Main 2020 (Online) 6th September Morning Slot Chemistry - Hydrocarbons Question 91 English
Answer
(A)
JEE Main 2020 (Online) 6th September Morning Slot Chemistry - Hydrocarbons Question 91 English Option 1
15
The species that has a spin-only magnetic moment of 5.9 BM, is :
(Td = tetrahedral)
Answer
(A)
[MnBr4]2– (Td)
16
Arrange the following solutions in the decreasing order of pOH :

(A) 0.01 M HCl
(B) 0.01 M NaOH
(C) 0.01 M CH3COONa
(D) 0.01 M NaCl
Answer
(B)
(A) > (D) > (C) > (B)
17
For the reaction

Fe2N(s) + $${3 \over 2}$$H2(g) ⇌ 2Fe(s) + NH3(g)
Answer
(A)
KC = Kp(RT)1/2
18
A solution of two components containing n1 moles of the 1st component and n2 moles of the 2nd component is prepared. M1 and M2 are the molecular weights of component 1 and 2 respectively. If d is the density of the solution in g mL–1, C2 is the molarity and x2 is the mole fraction of the 2nd component, then C2 can be expressed as :
Answer
(B)
$${C_2} = {{1000d{x_2}} \over {{M_1} + {x_2}\left( {{M_2} - {M_1}} \right)}}$$
19
The increasing order of pKb values of the following compounds is :

JEE Main 2020 (Online) 6th September Morning Slot Chemistry - Compounds Containing Nitrogen Question 155 English
Answer
(A)
I < II < IV < III