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JEE Main 2021 (Online) 20th July Evening Shift

JEE Main / 30 questions

2026Tue, Jul 20, 2021 9:30 AM30 PYQs
1Aldehydes Ketones And Carboxylic Acids
The major product (P) in the following reaction is :
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2Aldehydes Ketones And Carboxylic Acids
The correct order of their reactivity towards hydrolysis at room temperature is :
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3Basics Of Organic Chemistry
Which one of the following pairs of isomers is an example of metamerism?
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4Basics Of Organic Chemistry
When 0.15 g of an organic compound was analyzed using Carius method for estimation of bromine, 0.2397 g of AgBr was obtained. The percentage of bromine in the organic compound is ______________. (Nearest integer)[Atomic mass : Silver = 108,...
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5Biomolecules
Which one of the following statements is not true about enzymes?
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6Chemical Bonding And Molecular Structure
The hybridisations of the atomic orbitals of nitrogen in NO\(_2^ -\), NO\(_2^ +\) and NH\(_4^ +\) respectively are.
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7Chemical Kinetics And Nuclear Chemistry
\(PC{l_5}(g) \to PC{l_3}(g) + C{l_2}(g)\)In the above first order reaction the concentration of PCl5 reduces from initial concentration 50 mol L\(-\)1 to 10 mol L\(-\)1 in 120 minutes at 300 K. The rate constant for the reaction at 300 K is...
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8Compounds Containing Nitrogen
In the above reactions, product A and product B respectively are :
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9Compounds Containing Nitrogen
Consider the above reaction, compound B is :
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10Coordination Compounds
Spin only magnetic moment of an octahedral complex of Fe2+ in the presence of a strong field ligand in BM is :
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11Coordination Compounds
Which one of the following species doesn't have a magnetic moment of 1.73 BM, (spin only value)?
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12Coordination Compounds
An aqueous solution of NiCl2 was heated with excess sodium cyanide in presence of strong oxidizing agent to form [Ni(CN)6]2\(-\). The total change in number of unpaired electrons on metal centre is _______________.
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13Electrochemistry
Potassium chlorate is prepared by electrolysis of KCl in basic solution as shown by following equation.6OH\(-\) + Cl\(-\) \(\to\) ClO3\(-\) + 3H2O + 6e\(-\)A current of xA has to be passed for 10h to produce 10.0g of potassium chlorate. The...
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14Environmental Chemistry
Which one of the following gases is reported to retard photosynthesis?
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15Hydrocarbons
Metallic sodium does not react normally with :
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16Hydrocarbons
Benzene on nitration gives nitrobenzene in presence of HNO3 and H2SO4 mixture, where :
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17Hydrocarbons
Major product P of above reaction, is :
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18Hydrogen
The single largest industrial application of dihydrogen is :
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19Ionic Equilibrium
A solution is 0.1 M in Cl\(-\) and 0.001 M in CrO\(_4^{2 - }\). Solid AgNO3 is gradually added to it. Assuming that the addition does not change in volume and Ksp(AgCl) = 1.7 \(\times\) 10\(-\)10 M2 and Ksp(Ag2CrO4) = 1.9 \(\times\) 10\(-\)...
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20Isolation Of Elements
Consider two chemical reactions (A) and (B) that take place during metallurgical process:(A) \(ZnC{O_{3(s)}}\buildrel \Delta \over \longrightarrow Zn{O_{(s)}} + C{O_{2(g)}}\)(B) $$2Zn{S_{(s)}} + 3{O_{2(g)}}\buildrel \Delta \over
\longri...
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21Polymers
Bakelite is a cross-linked polymer of formaldehyde and :
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22Practical Organic Chemistry
In Carius method, halogen containing organic compound is heated with fuming nitric acid in the presence of :
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23Salt Analysis
Cu2+ salt reacts with potassium iodide to give
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24Solid State
Diamond has a three dimensional structure of C atoms formed by covalent bonds. The structure of diamond has face centred cubic lattice where 50% of the tetrahedral voids are also occupied by carbon atoms. The number of carbon atoms present...
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25Solutions
The vapour pressures of A and B at 25\(^\circ\)C are 90 mm Hg and 15 mm Hg respectively. If A and B are mixed such that the mole fraction of A in the mixture is 0.6, then the mole fraction of B in the vapour phase is x \(\times\) 10\(-\)1. ...
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26Some Basic Concepts Of Chemistry
4g equimolar mixture of NaOH and Na2CO3 contains x g of NaOH and y g of Na2CO3. The value of x is ____________ g. (Nearest integer)
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27Structure Of Atom
Outermost electronic configuration of a group 13 element, E, is 4s2, 4p1. The electronic configuration of an element of p-block period-five placed diagonally to element, E is :
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28Structure Of Atom
The wavelength of electrons accelerated from rest through a potential difference of 40 kV is x \(\times\) 10\(-\)12 m. The value of x is ___________. (Nearest integer)Give : Mass of electron = 9.1 \(\times\) 10\(-\)31 kgCharge on an electro...
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29Surface Chemistry
100 ml of 0.0018% (w/v) solution of Cl\(-\) ion was the minimum concentration of Cl\(-\) required to precipitate a negative sol in one h. The coagulating value of Cl\(-\) ion is _________ (Nearest integer)
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30Thermodynamics
For a given chemical reaction A \(\to\) B at 300 K the free energy change is \(-\)49.4 kJ mol\(-\)1 and the enthalpy of reaction is 51.4 kJ mol\(-\)1. The entropy change of the reaction is _____________ JK\(-\)1 mol\(-\)1.
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