List of top Chemistry Questions asked in JEE Main

In following pairs, the one in which both transition metal ions are colourless is :
Observe structures of the following compounds

The total number of structures/compounds which possess asymmetric carbon atoms is _____.
Which of the given reactions is not an example of a disproportionation reaction?
Using very little soap while washing clothes, does not serve the purpose of cleaning of clothes, because:
Ionic radii of cation A+ and anion B– are 102 and 181 pm, respectively. These ions are allowed to crystallize into an ionic solid. This crystal has cubic close packing for B–. A+ is present in all octahedral voids. The edge length of the unit cell of the crystal AB is _____pm. (Nearest integer)
Match List I with List II
List I EnzymeList II Conversion of
AInvertaseIStarch into maltose
BZymaseIIMaltose into glucose
CDiastaseIIIGlucose into ethanol
DMaltaseIVCane sugar into glucose

Choose the most appropriate answer from the options given below:

\(BeO\) reacts with \(HF\) in presence of ammonia to give \([A]\) which on thermal decomposition produces \([B]\) and ammonium fluoride. Oxidation state of Be in \([A]\) is _______
The major product in the given reaction is
Question Reaction
The IUPAC name of ethylidene chloride is:
‘A’ and ‘B’ respectively are: \(A\xrightarrow[(2)Zn-H_2O]{(1)O_3}\)
\(Ethane-1, 2-dicarbaldehyde + Glyoxal/Oxaldehyde\)
\(B \xrightarrow[(2)Zn-H_2O]{(1)O_3}   5 - oxohexanal\)
4.0 moles of argon and 5.0 moles of PCl5 are introduced into an evacuated flask of 100 litre capacity at 610 K. The system is allowed to equilibrate. At equilibrium, the total pressure of mixture was found to be 6.0 atm. The Kp for the reaction is
 [Given : R = 0.082 L atm K–1 mol–1 ]
Which of the following ketone will NOT give enamine on treatment with secondary amines? [where t-Bu is –C(CH3)3]
Given below are two statements: one is labelled as Assertion A and, the other is labelled as Reason R.
Assertion A: [6] Annulene, [8] Annulene and cis-[10] Annulene, are respectively aromatic, not-aromatic and aromatic.
Reason R: Planarity is one, of the requirements of aromatic systems.
In the light of the above statements, choose the most appropriate answer from the options given below.
The Novolac polymer has mass of 963 g. The number of monomer units present in it are
The rate constant for a first order reaction is given by the following equation :
\(ln\ k=33.24−\frac {2.0×10^4\ K}{T}\)
The activation energy for the reaction is given by ______ \(kJ mol^{–1}\). (In nearest integer)
(Given : \(R = 8.3 JK^{–1} mol^{–1}\))

A solution of Fe2(SO4)3 is electrolyzed for ‘x’ min with a current of 1.5 A to deposit 0.3482 g of Fe. The value of x is _______. [nearest integer]

Given : 1 F = 96500 C mol–1. 

Atomic mass of Fe = 56 g mol–1

The standard free energy change \((ΔG°)\) for \(50%\) dissociation of \(N_2O_4\) into \(NO_2\) at \(27°C\) and 1 atm pressure is \(x\ J mol^{–1}\). The value of \(x\) is _____. (Nearest Integer)
[Given : \(R = 8.31\ JK^{–1} mol^{–1}\), \(log\ 1.33 = 0.1239\), \(ln\ 10 = 2.3\)]

pH value of 0.001 M NaOH solution is _______.

Which of the following sets are correct regarding polymer?
  1. Copolymer : Buna-S
  2. Condensation polymer : Nylon-6,6
  3. Fibres : Nylon-6,6
  4. Thermosetting polymer : Terylene
  5. Homopolymer : Buna-N
Choose the correct answer from given options below
Match List-I with List-II.
 (Si-Compounds) (Si-Polymeric/other
Products)
A.\((CH_3)_4Si\)iChain Silicone
B.\((CH_3)Si(OH)_3\)iiDimeric Silicone
C.\((CH_3)_2Si(OH)_2\)iiiSilane
D.\((CH_3)_3Si(OH)\)iv2D-Silicone

Choose the correct answer from the options given below:

The major product of the following reaction is:
 Chemical Reaction With No2FI
Given below are two statements: one is labelled as Assertion A and the other is labelled as Reason R. 
Assertion A : \(LiF\) is sparingly soluble in water.
Reason R : The ionic radius of \(Li^+\) ion is smallest among its group members, hence has least hydration enthalpy.
In the light of the above statements, choose the most appropriate answer from the options given below.
Which statement is not true with respect to nitrate ion test?

The normality of H2SO4 in the solution obtained on mixing 100 mL of 0.1 M H2SO4 with 50 mL of 0.1 M NaOH is ________ × 10–1 N. (Nearest Integer)

Lithium nitrate and sodium nitrate, when heated separately, respectively, give :