List of top Questions asked in JEE Main

The Novolac polymer has mass of 963 g. The number of monomer units present in it are
Which of the following ketone will NOT give enamine on treatment with secondary amines? [where t-Bu is –C(CH3)3]

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 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 : \(R = 8.3 JK^{–1} mol^{–1}\))
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

pH value of 0.001 M NaOH solution is _______.

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 ]
The major product in the given reaction is
Question Reaction
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)

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.
The hybridization of P exhibited in \(PF_5\) is \(sp_xd_y\). The value of y is _____ .
\(2\ g\) of a non-volatile non-electrolyte solute is dissolved in \(200\ g\) of two different solvents A and B whose ebullioscopic constants are in the ratio of \(1:8\). The elevation in boiling points of A and B are in the ratio \(\frac xy\ (x : y)\). The value of \(y\) is ______ . (Nearest Integer)
\(\dot Cl + CH_4 → A + B\)
A and B in the above atmospheric reaction step are:
During halogen test, sodium fusion extract is boiled with concentrated HNO3 to

For the reaction taking place in the cell: 
Pt(s) | H2(g) | H+ (q) || Ag+(aq) | Ag(s), 
Eocell = + 0.5332 V. 
The value of ΔfGo is _____kJ mol–1 [in nearest integer]

Given below are two statements: one is labelled as Assertion A and other is labelled as Reason R.
Assertion A : Finest gold is red in colour, as the size of the particles increases, it appears purple then blue and finally gold.
Reason R : The colour of the colloidal solution depends on the wavelength of light scattered by the dispersed particles.
In the light of the above statements, choose the most appropriate answer from the options given below.
The product formed in the following reaction.
The product formed in the reaction
Given below are two statements:
Statement I : According to the Ellingham diagram, any metal oxide with higher ΔG° is more stable than the one with lower ΔG°.
Statement II :The metal involved in the formation of oxide placed lower in the Ellingham diagram can reduce the oxide of a metal placed higher in the diagram.
In the light of the above statements, choose the most appropriate answer from the options given below
Among the following ores Bauxite, Siderite, Cuprite, Calamine, Haematite, Kaolinite, Malachite, Magnetite, Sphalerite, Limonite, Cryolite, the number of principal ores of iron is____.
Number of lone pair(s) of electrons on central atom and the shape of BrF3 molecule respectively, are
Haemoglobin contains \(0.34\%\) of iron by mass. The number of Fe atoms in \(3.3\) g of haemoglobin is(Given: Atomic mass of Fe is \(56\) u, \(N_A\) = \(6.022 × 1023\) \(mol^{–1}\))
The molar heat capacity for an ideal gas at constant pressure is 20.785 J K–1 mol–1. The change in internal energy is 5000 J upon heating it from 300 K to 500 K. The number of moles of the gas at constant volume is _____. (Nearest integer)
(Given : R = 8.314 JK-1mol-1).
An organic compound ‘A’ contains nitrogen and chlorine. It dissolves readily in water to give a solution that turns litmus red. Titration of compound ‘A’ with standard base indicates that the molecular weight of ‘A’ IS 131±2. When a sample of ‘A’ is treated with aq. NaOH, a liquid separates which contains N but not Cl. Treatment of the obtained liquid with nitrous acid followed by phenol gives orange precipitate. The compound A is :
Which one of the following is a reducing sugar?