List of top Questions asked in JEE Main

During water-gas shift reaction

Which of the following statement (s) is (are) correct?
(a) The pH of 1 .0 x 10-8M solution of HCl is 8  
(b) The conjugate base of H2PO-4 is HPOI2-4  
(c) Autoprotolysis constant of water increases with temperature 
(d) When a solution of a weak monoprotic acid is treated against a strong base, at half - neutralisation point pH = (\(\frac{1}{2}\))pK_a.
Choose the correct answer from the the options given below

Consider the following statements:
(A) NF3 molecule has a trigonal planar structure. 
(B) Bond length of N2 is shorter than O2. 
(C) Isoelectronic molecules or ions have identical bond order. 
(D) Dipole moment of H2S is higher than that of water molecule. 
Choose the correct answer from the option below

Which of the following expressions is correct in case of a C_SCl unit cell (edge length, a) ?

In potassium ferrocyanide, there are ____ pairs of electrons in the \(t_{2g}\) set of orbitals.

A molecule undergoes two independent first order reactions whose respective half lives are 12 min and 3 min. If both the reactions are occurring then the time taken for the 50% consumption of the reactant is _____ min. (Nearest integer)

\(FeO^{2-}_4+\underrightarrow{2.2v}\;Fe^{3+}\underrightarrow{+0.70v}\;Fe^{2+}\underrightarrow{-0.45v}\;Fe^0\)
\(E^0_{FeO_4^{2+}}\; is \;x × 10^{-3} V\). The Value of \(x\) is __

The number of correct statement/s involving equilibria in physical process from the following is
(A) Equilibrium is possible only in a closed system at a given temperature 
(B) Both the opposing processes occur at the same rate. 
(C) When equilibrium is attained at a given temperature, the value of all its parameters became equal 
(D) For dissolution of solids in liquids, the solubility is constant at a given temperature

The number of incorrect statement/s about the black body from the following is _______
(A) Emit or absorb energy in the form of electromagnetic radiation 
(B) Frequency distribution of the emitted radiation depends on temperature
(C) At a given temperature, intensity vs frequency curve passes through a maximum value 
(D) The maximum of the intensity vs frequency curve is at a higher frequency at higher temperature compared to that at lower temperature

Match List I with List II

List-I	Polymer	List-II	Type/ Class
(A)	Nylon-2-Nylon-6	(I)	Thermosetting polymer
(B)	Buna-N	(II)	Biodegradable polymer
(C)	Urea-formaldehyde	(III)	Synthetic rubber resin
(D)	Dacron	(IV)	Polyester

Choose the correct answer from the options given below:

Isomeric amines with molecular formula C₈ H₁₁N give the following tests
Isomer (P) ⇒ Can be prepared by Gabriel phthalimide synthesis
Isomer (Q) ⇒ Reacts with Hinsberg’s reagent to give solid insoluble in NaOH
Isomer (R) ⇒ Reacts with HONO followed by β-naphthol in NaOH to give red dye.
Isomers (P), (Q) and (R) respectively are

Suitable reaction condition for preparation of Methyl phenyl ether is

The major product ‘P’ formed in the given reaction is

The pair of compounds from the following pairs having both the compounds with net non-zero dipole moment is

Using column chromatography, mixture of two compounds ‘A’ and ‘B’ was separated. ‘A’ eluted first, this indicates ‘B’ has

Match the following List-I and List-II:

List-I	Industry	List-II	Waste Generated
(A)	Steel Plants	(I)	Gypsum
(B)	Thermal Power Plants	(II)	Fly ash
(C)	Fertilizer industries	(III)	Slag
(D)	Ppaer mills	(IV)	Bio-degradable Wastes

Choose the correct answer from the options given below:

Which of the following statements are correct?
(A) The M³⁺/M²⁺ reduction potential for iron is greater than manganese 
(B) The higher oxidation states of first row dblock elements get stabilized by oxide ion. 
(C) Aqueous solution of Cr²⁺ can liberate hydrogen from dilute acid. 
(D) Magnetic moment of V²⁺ is observed between 4.4-5.2 BM Choose the correct answer from the options given below: 

Given below are two reactions, involved in the commercial production of dihydrogen (H₂). The two reactions are carried out at temperature “T₁ ” and “T₂ ” respectively
\(C(S)+H_2O(g)\underrightarrow {T_1}\;CO(g)+H_2(g)\)
\(CO(g)+H_2O(g)\underrightarrow{T_2}\;CO_2(g)+H_2(g)\)
The temperature \(T_1\) and \(T_2\) are correctly related as 

The de Broglie wavelength of a molecule in a gas at room tem perature (300 K) is λ₁. If the temperature of the gas is increased to 600 K, then the de Broglie wavelength of the same gas molecule becomes

A particle of mass m moving with a velocity v collides with a particle of mass 2m at rest and sticks to it. Velocity of the combined mass equal to? 

The range of the projectile projected at an angle of 15° with hor izontal is 50 m. If the projectile is projected with same velocity at an angle of 45° with horizontal, then its range will be

At what \(pH\), given half cell \(MnO _4^{-}(01 M ) \mid Mn ^{2+}(0001 M )\) will have electrode potential of \(1.282\, V\)? (Nearest Integer)
(Given: \(E _{ MnO _{4}^-| Mn ^{2+}}^{ o }=154 \,V , \frac{2303 RT }{ F }=0059\, V\))

(i) \(X ( g ) \rightleftharpoons Y ( g )+ Z\) (g) \(K _{ p 1}=3\)
(ii)\(A ( g ) \rightleftharpoons 2 B ( g )\,\, K _{ p 2}=1\)
If the degree of dissociation and initial concentration of both the reactants \(X ( g )\) and \(A ( g )\) are equal, then the ratio of the total pressure at equilibrium \(\left(\frac{p_1}{p_2}\right)\) is equal to \(x : 1\). The value of \(x\) is _________ (Nearest integer)