JEE MAIN - Chemistry (2021 - 20th July Morning Shift)

1
According to the valence bond theory the hybridization of central metal atom is dsp2 for which one of the following compounds?
Answer
(B)
$${K_2}[Ni{(CN)_4}]$$
2
The correct structure of Rhumann's Purple, the compound formed in the reaction of ninhydrin with proteins is :
Answer
(D)
JEE Main 2021 (Online) 20th July Morning Shift Chemistry - Compounds Containing Nitrogen Question 130 English Option 4
3
The correct order of intensity of colors of the compounds is :
Answer
(C)
$${[NiC{l_4}]^{2 - }} > {[Ni{({H_2}O)_6}]^{2 + }} > {[Ni{(CN)_4}]^{2 - }}$$
4
The species given below that does NOT show disproportionation reaction is :
Answer
(A)
$$BrO_4^ - $$
5
An inorganic Compound 'X' on treatment with concentrated H2SO4 produces brown fumes and gives dark brown ring with FeSO4 in presence of concentrated H2SO4. Also Compound 'X' gives precipitate 'Y', when its solution in dilute HCl is treated with H2S gas. The precipitate 'Y' on treatment with concentrated HNO3 followed by excess of NH4OH further gives deep blue coloured solution, Compound 'X' is :
Answer
(C)
Cu(NO3)2
6

Among the given species the Resonance stabilised carbocations are :
Answer
(C)
(A) and (B) only
7
In the given reaction

3-Bromo-2, 2-dimethyl butane $$\buildrel {{C_2}{H_5}OH} \over \longrightarrow \mathop {'A'}\limits_{(Major\,\Pr oduct)} $$

Product A is :
Answer
(C)
2-Ethoxy-2, 3-dimethyl butane
8
Compound A is converted to B on reaction with CHCl3 and KOH. The compound B is toxic and can be decomposed by C. A, B and C respectively are :
Answer
(C)
primary amine, isonitrile compound, conc. HCl
9
Identify the incorrect statement from the following
Answer
(A)
Amylose is a branched chain polymer of glucose
10
JEE Main 2021 (Online) 20th July Morning Shift Chemistry - Aldehydes, Ketones and Carboxylic Acids Question 124 English
Which among the above compound/s does/do not form Silver mirror when treated with Tollen's reagent?
Answer
(C)
Only (II)
11
JEE Main 2021 (Online) 20th July Morning Shift Chemistry - Hydrocarbons Question 77 English
For above chemical reactions, identify the correct statement from the following :
Answer
(D)
Compound 'A' is dicarboxylic acid and compound 'B' is diol
12
The number of lone pairs of electrons on the central I atom in I$$_3^ - $$ is ____________.
Answer
3
13
250 mL of 0.5 M NaOH was added to 500 mL of 1 M HCl. The number of unreacted HCl molecules in the solution after complete reaction is ___________ $$\times$$ 1021. (Nearest integer)

(NA = 6.022 $$\times$$ 1023)
Answer
226
14
The Azimuthal quantum number for the valence electrons of Ga+ ion is ___________.

(Atomic number of Ga = 31)
Answer
0
15
The spin-only magnetic moment value for the complex [Co(CN)6]4$$-$$ is __________ BM.

[At. no. of Co = 27]
Answer
2
16
2SO2(g) + O2(g) $$\rightleftharpoons$$ 2SO3(g)

In an equilibrium mixture, the partial pressures are

PSO3 = 43 kPa; PO2 = 530 Pa and PSO2 = 45 kPa. The equilibrium constant KP = ___________ $$\times$$ 10$$-$$2. (Nearest integer)
Answer
172
17
The number of nitrogen atoms in a semicarbazone molecule of acetone is ______________.
Answer
3
18
To synthesize 1.0 mole of 2-methylpropan-2-ol from Ethylethanoate ___________ equivalents of CH3MgBr Reagent will be required. (Integer value)
Answer
2
19
The inactivation rate of a viral preparation is proportional to the amount of virus. In the first minute after preparation, 10% of the virus is inactivated. The rate constant for viral inactivation is ___________ $$\times$$ 10$$-$$3 min$$-$$1. (Nearest integer)

[Use : ln 10 = 2.303; log10 3 = 0.477; property
of logarithm : log xy = y log x]
Answer
106
20
An average person needs about 10000 kJ energy per day. The amount of glucose (molar mass = 180.0 g mol$$-$$1) needed to meet this energy requirement is ____________ g.

(Use : $$\Delta$$CH(glucose) = $$-$$2700 kJ mol$$-$$1)
Answer
667
21
At 20$$^\circ$$ C, the vapour pressure of benzene is 70 torr and that of methyl benzene is 20 torr. The mole fraction of benzene in the vapour phase at 20$$^\circ$$ above an equimolar mixture of benzene and methyl benzene is _____________ $$\times$$ 10$$-$$2. (Nearest integer)
Answer
78