List of top Chemistry Questions asked in JEE Main

9.3 g of pure aniline upon diazotisation followed by coupling with phenol gives an orange dye. The mass of orange dye produced (assume 100% yield/ conversion) is ________g. (nearest integer)
The difference in the 'spin-only' magnetic moment values of \( \text{KMnO}_4 \) and the manganese product formed during titration of \( \text{KMnO}_4 \) against oxalic acid in acidic medium is ______ BM (nearest integer).
Number of molecules from the following which can exhibit hydrogen bonding is ______. (nearest integer)
Which among the following aldehydes is most reactive towards nucleophilic addition reactions?
At \(-20^\circ \text{C}\) and 1 atm pressure, a cylinder is filled with an equal number of \(H_2\), \(I_2\), and \(HI\) molecules for the reaction:
\[H_2(g) + I_2(g) \rightleftharpoons 2HI(g)\] The \(K_P\) for the process is \(x \times 10^{-1}\).
\(x = ___________)
Given: \(R = 0.082 \, \text{L atm K}^{-1} \text{mol}^{-1}\)
The density of 'x' M solution ('x' molar) of NaOH is \(1.12 \, \text{g/mL}\). While in molality, the concentration of the solution is \(3 \, \text{m}\) (3 molal). Then x is:
Given: Molar mass of NaOH is \(40 \, \text{g/mol}\)
The electron affinity values are negative for:
A. Be → Be−
B. N → N−
C. O → O2−
D. Na → Na−
E. Al → Al−
Choose the most appropriate answer from the options given below:
The number of element from the following that do not belong to lanthanoids is :
Eu, Cm, Er, Tb, Yb and Lu
Match List-I with the List-II
List-I
(Compound)		List-II
(Uses)
(A) Iodoform(I) Fire extinguisher
(B) Carbon
tetrachloride		(II) Insecticide
(C) CFC(III) Antiseptic
(D) DDT(IV) Refrigerants
Choose the correct answer from the options given below:
Which of the following material is not a semiconductor.
Which of the following statements are correct ?
A. Glycerol is purified by vacuum distillation because it decomposes at its normal boiling point
B. Aniline can be purified by steam distillation as aniline is miscible in water.
C. Ethanol can be separated from ethanol water mixture by azeotropic distillation because it forms azeotrope.
D. An organic compound is pure, if mixed M.P. is remained same.
Choose the most appropriate answer from the options given below :
In Reimer - Tiemann reaction, phenol is converted into salicylaldehyde through an intermediate. The structure of intermediate is ______.
Match List-I with the List-II
List-I
(Compound /
Species)		List-II
(Shape / Geometry)
(A) \(SF_4\)(I) Tetrahedral
(B) \(BrF_3\)(II) Pyramidal
(C) \(BrO_{3}^{-}\)(III) See saw
(D) \(NH^{+}_{4}\)(IV) Bent T-shape
Choose the correct answer from the options given below:
Match List-I with the List-II
List-I
(Precipitating reagent and
conditions)		List-II
(Cation)
(A) \(NH_4Cl + NH_4OH\)(I) Mn2+
(B) \(NH_4OH + Na_2CO_3\)(II) Pb2+
(C) \(NH_4OH + NH_4Cl + H_2S gas\)(III) Al3+
(D) dilute HCl(IV) Sr2+
Choose the correct answer from the options given below:
Consider the following complexes:
\([CoCl(NH_3)_5]^{2+}\) (A)
\([Co(CN)_6]^{3-}\) (B)
\([Co(NH_3)_5(H_2O)]^{3+}\) (C)
\([Cu(H_2O)_4]^{2+}\) (D)
The correct order of A, B, C, and D in terms of wavenumber of light absorbed is:
DNA molecule contains 4 bases whoes structure are shown below. One of the structure is not correct, identify the incorrect base structure.
Functional group present in sulphonic acid is :
Match List-I with the List-II
List-I
(Molecule / Species)		List-II
(Property / Shape)
(A) \(SO_2Cl_2\)(I) Paramagnetic
(B) NO(II) Diamagnetic
(C) \(NO^{-}_{2}\)(III) Tetrahedral
(D) \(I^{-}_{3}\)(IV) Linear
Choose the correct answer from the options given below:
Given below are two statements:
Statement I : Picric acid is 2, 4, 6-trinitrotoluene.
Statement II : Phenol-2, 4-disulphuric acid is treated with conc. HNO3 to get picric acid.
In the light of the above statement, choose the most appropriate answer from the options given below:
Match List-I with the List-II
List-I
(Hybridization)		List-II
(Orientation in
Space)
(A) sp3(I) Trigonal
bipyramidal
(B) dsp2(II) Octahedral
(C) sp3d(III) Tetrahedral
(D) sp3d2(IV) Square planar
Choose the correct answer from the options given below:
Given below are two statements :
Statement I : Gallium is used in the manufacturing of thermometers.
Statement II : A thermometer containing gallium is useful for measuring the freezing point (256 K) of brine solution.
In the light of the above statement, choose the correct answer from the options given below :
Which of the following is metamer of the given compound (X) ?
Among $VO_2^+$, $MnO_4^-$, and $Cr_2O_7^{2-}$, the spin-only magnetic moment value of the species with least oxidising ability is _____________ BM (Nearest integer).(Given atomic number $V = 23$, $Mn = 25$, $Cr = 24$)
Consider the two different first-order reactions given below: \[\text{A + B} \rightarrow \text{C (Reaction 1)} \\\text{P} \rightarrow \text{Q (Reaction 2)}\]The ratio of the half-life of Reaction 1 : Reaction 2 is $5 : 2$. If $t_1$ and $t_2$ represent the time taken to complete $\frac{2}{3}^\text{rd}$ and $\frac{4}{5}^\text{th}$ of Reaction 1 and Reaction 2, respectively, then the value of the ratio $t_1 : t_2$ is ____ $\times 10^{-1}$ (nearest integer).[Given: $\log_{10}(3) = 0.477$ and $\log_{10}(5) = 0.699$]
For the reaction at $298 \, \text{K}$, $2\text{A} + \text{B} \rightarrow \text{C}$. $\Delta H = 400 \, \text{kJ mol}^{-1}$ and $\Delta S = 0.2 \, \text{kJ mol}^{-1} \, \text{K}^{-1}$. The reaction will become spontaneous above ____ $\text{K}$.