List of top Chemistry Questions asked in JEE Main

If $a_0$ is denoted as the Bohr radius of the hydrogen atom, then what is the de-Broglie wavelength $\lambda$ of the electron present in the second orbit of hydrogen atom? ( $n$ : any integer)

Match the Compounds (List- I) with the appropriate Catalyst/Reagents (List- II) for their reduction into corresponding amines.

When sec-butylcyclohexane reacts with bromine in the presence of sunlight, the major product is:

Assume a living cell with 0.9% ( $w/w$ ) of glucose solution (aqueous). This cell is immersed in another solution having equal mole fraction of glucose and water. (Consider the data up to first decimal place only) The cell will:

Consider the following data:
- Heat of formation of $CO_2(g)$ = -393.5 kJ mol $^{-1}$
- Heat of formation of $H_2O(l)$ = -286.0 kJ mol $^{-1}$
- Heat of combustion of benzene = -3267.0 kJ mol $^{-1}$
The heat of formation of benzene is ……… kJ mol $^{-1}$ (Nearest integer).

The spin-only magnetic moment ( $\mu$ ) value (B.M.) of the compound with the strongest oxidising power among $Mn_2O_3$ , $TiO$ , and $VO$ is ……. B.M. (Nearest integer).

Concentrated nitric acid is labelled as 75% by mass. The volume in mL of the solution which contains 30 g of nitric acid is:
Given: Density of nitric acid solution is 1.25 g/mL.

Arrange the following in increasing order of solubility product:
${Ca(OH)}_2, {AgBr}, {PbS}, {HgS}$

Which of the following is/are correct with respect to the energy of atomic orbitals of a hydrogen atom?
(A) $1s<2s<2p<3d<4s$
(B) $1s<2s = 2p<3s = 3p$
(C) $1s<2s<2p<3s<3p$
(D) $1s<2s<4s<3d$
Choose the correct answer from the options given below:

Match List - I with List - II.
List - I (Saccharides)     List - II (Glycosidic linkages found)
(A) Sucrose     (I) $\alpha 1 - 4$
(B) Maltose     (II) $\alpha 1 - 4$ and $\alpha 1 - 6$
(C) Lactose     (III) $\alpha 1 - \beta 2$
(D) Amylopectin     (IV) $\beta 1 - 4$

Choose the correct answer from the options given below:

Total number of molecules/species from the following which will be paramagnetic is ………. $O_2, O_2^+, O_2^-, NO, NO_2, CO, K_2[NiCl_4], [Co(NH_3)_6]Cl_3, K_2[Ni(CN)_4]$

A group 15 element forms $d\pi - d\pi$ bond with transition metals. It also forms a hydride, which is the strongest base among the hydrides of other group members that form $d\pi - d\pi$ bonds. The atomic number of the element is …….

The total number of compounds from below when treated with hot KMnO4 giving benzoic acid is:

Given below are two statements:

Statement (I):
are isomeric compounds.

Statement (II):
are functional group isomers.

In the light of the above statements, choose the correct answer from the options given below:

The major product of the following reaction is:

The purification method based on the following physical transformation is:

{Solid} \xrightarrow{{Heat}} {Vapour} \xrightarrow{{Cool}} {Solid}

Consider an elementary reaction:

A(g) + B(g) \rightarrow C(g) + D(g)

If the volume of the reaction mixture is suddenly reduced to $\frac{1}{3}$ of its initial volume, the reaction rate will become $x$ times of the original reaction rate. The value of $x$ is:

Identify correct statements:
(A) Primary amines do not give diazonium salts when treated with ${NaNO}_2$ in acidic condition.
(B) Aliphatic and aromatic primary amines on heating with ${CHCl}_3$ and ethanolic ${KOH}$ form carbylamines.
(C) Secondary and tertiary amines also give carbylamine test.
(D) Benzenesulfonyl chloride is known as Hinsberg’s reagent.
(E) Tertiary amines react with benzenesulfonyl chloride very easily.
Choose the correct answer from the options given below:

An ideal gas undergoes a cyclic transformation starting from point A and coming back to the same point by tracing the path A→B→C→D→A as shown in the three cases below.

Choose the correct option regarding $\Delta U$ :

Match List - I with List - II.

List - I (Complex)	List - II (Hybridisation)
(A) $[\text{CoF}_6]^{3-}$	(I) $d^2 sp^3$
(B) $[\text{NiCl}_4]^{2-}$	(II) $sp^3$
(C) $[\text{Co(NH}_3)_6]^{3+}$	(III) $sp^3 d^2$
(D) $[\text{Ni(CN}_4]^{2-}$	(IV) $dsp^2$

Choose the correct answer from the options given below:

Identify correct conversion during acidic hydrolysis from the following:
(A) Starch gives galactose.
(B) Cane sugar gives equal amount of glucose and fructose.
(C) Milk sugar gives glucose and galactose.
(D) Amylopectin gives glucose and fructose.
(E) Amylose gives only glucose.
Choose the correct answer from the options given below:

Identify the inorganic sulphides that are yellow in colour:
(A) $({NH}_4)_2{S}$
(B) ${PbS}$
(C) ${CuS}$
(D) ${As}_2{S}_3$
(E) ${As}_2{S}_5$
Choose the correct answer from the options given below:

Given below are two statements:
Statement (I): According to the Law of Octaves, the elements were arranged in the increasing order of their atomic number.
Statement (II): Meyer observed a periodically repeated pattern upon plotting physical properties of certain elements against their respective atomic numbers.
In the light of the above statements, Choose the correct answer from the options given below:

For bacterial growth in a cell culture, growth law is very similar to the law of radioactive decay. Which of the following graphs is most suitable to represent bacterial colony growth? Where $N$
- Number of Bacteria at any time, $N_0$
- Initial number of Bacteria.

Identify product [A], [B], and [C] in the following reaction sequence.