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JEE Main 2021 (Online) 27th August Morning Shift

JEE Main / 30 questions

2026Fri, Aug 27, 2021 3:30 AM30 PYQs
1Alcohols Phenols And Ethers
In the following sequence of reactions, the final product D is :
MCQ+4 / -12021
2Alcohols Phenols And Ethers
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 so...
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3Aldehydes Ketones And Carboxylic Acids
The structure of the starting compound P used in the reaction given below is :
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4Biomolecules
Out of following isomeric forms of uracil, which one is present in RNA?
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5Chemical Bonding And Molecular Structure
Match List - I with List - II :Choose the most appropriate answer from the options given below :
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6Chemical Bonding And Molecular Structure
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)
Paramagneti...
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7Chemical Equilibrium
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 n...
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8Chemical Kinetics And Nuclear Chemistry
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...
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9Chemistry In Everyday Life
The correct statement about (A), (B), (C) and (D) is :
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10Compounds Containing Nitrogen
The major product of the following reaction is :
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11Compounds Containing Nitrogen
Which of the following is not a correct statement for primary aliphatic amines?
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12Coordination Compounds
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)
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13D And F Block Elements
The nature of oxides V2O3 and CrO is indexed as 'X' and 'Y' type respectively. The correct set of X and Y is :
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14D And F Block Elements
The number of f electrons in the ground state electronic configuration of Np (Z = 93) is ___________. (Nearest integer)
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15Environmental Chemistry
The gas 'A' is having very low reactivity reaches to stratosphere. It is non-toxic and non-flammable but dissociated by UV-radiations in stratosphere. The intermediates formed initially from the gas 'A' are :
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16Gaseous State
The unit of the van der Waals gas equation parameter 'a' in \(\left( {P + {{a{n^2}} \over {{V^2}}}} \right)(V - nb) = nRT\) is :
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17Haloalkanes And Haloarenes
In the following sequence of reactions the P is :
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18Hydrogen
Deuterium resembles hydrogen in properties but :
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19Isolation Of Elements
Which refining process is generally used in the purification of low melting metals?
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20P Block Elements
In which one of the following molecules strongest back donation of an electron pair from halide to boron is expected?
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21P Block Elements
In polythionic acid, H2SxO6 (x = 3 to 5) the oxidation state(s) of sulphur is/are :
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22Practical Organic Chemistry
Acidic ferric chloride solution on treatment with excess of potassium ferrocyanide gives a Prussian blue coloured colloidal species. It is :
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23Practical Organic Chemistry
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)
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24Practical Organic Chemistry
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 __________...
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25S Block Elements
The number of water molecules in gypsum, dead burnt plaster and plaster of Paris, respectively are :
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26Solutions
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]
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27Some Basic Concepts Of Chemistry
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]
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28Structure Of Atom
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]
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29Surface Chemistry
Tyndall effect is more effectively shown by :
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30Thermodynamics
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 ______...
INTEGER+4 / -12021

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