List of top Chemistry Questions asked in JEE Main

Given below are two statements :
Statement I : Presence of large number of unpaired electrons in transition metal atoms results in higher enthalpies of their atomisation.
Statement II : $d_{xy} = d_{xz} = d_{yz} < d_{x^2 - y^2} = d_{z^2}$ and $d_{x^2 - y^2} = d_{z^2} = d_{xy} <d_{xz} = d_{yz}$ are the d-orbital splittings in $[Fe(H_2O)_6]^{3+}$ and $[Ni(Cl)_4]^{2-}$ complex ions respectively.
In the light of the above statements, choose the correct answer from the options given below :

A paper dipped in a dil. $H_2SO_4$ solution of 'X' upon treatment with $SO_2$ gas turns into green. The compound 'X' is :

RMgI when treated with ice cold water liberated a gas which occupied 1.4 dm$^3$/g at STP. The gas produced is further reacted with iodine in presence of $HIO_3$ to give compound (X). Compound (X) in presence of Na and dry ether produced compound (Y). Molar mass of compound (Y) is ______ g mol$^{-1}$. (Nearest integer)}

For a reaction $A \to P$ at $T$ K, the half life ($t_{1/2}$) is plotted as a function of initial concentration $[A]_o$ of A as given below. The value of $x$ in the given figure is ______ s (Nearest integer)}

20 g hemoglobin in a 1 L aqueous solution (A) at 300 K is separated from pure water by semi permeable membrane. At equilibrium the height of solution in a tube dipped in a solution (A) is found to be 80.0 mm higher than the tube dipped in water. The molar mass of hemoglobin is ______ kg mol$^{-1}$. (Nearest integer)
(Given : $g=10 \text{ m s}^{-2}$, $R=8.3 \text{ kPa dm}^3 \text{ K}^{-1}\text{mol}^{-1}$, density of solution $= 1000 \text{ kg m}^{-3}$)}

Given below are two statements :
Statement I : The condensation reaction between $CH_3-CH=O$ and

under optimum pH will produce

.
Statement II : The molecule,

will generate $Ph-CH=O$ in the presence of dilute acid.
In the light of the above statements, choose the correct answer from the options given below :

Given below are two statements :
Statement I : Aluminium upon reaction with NaOH forms $[Al(OH)_6]^{3-}$ ion.
Statement II : The geometry of $ICl_4^-$, $ClO_3^-$ and $IBr_2^-$ is square planar, pyramidal and linear respectively.
In the light of the above statements, choose the correct answer from the options given below :

Given below are two statements :
Statement I :

$\alpha$ and $\beta$ D-(+)-glucose are two anomers of D-(+)-glucose.
Statement II : The open chain forms of D-glucose and D-fructose contain three similar chiral carbons at $C_3, C_4$ and $C_5$.
In the light of the above statements, choose the correct answer from the options given below :}

Consider the following data for the reaction
$X_2(g) + Y_2(g) \rightleftharpoons 2XY(g)$
at 600 K. The $\Delta_r G^\ominus$ (in kJ $\text{mol}^{-1}$) for the reaction is :}

Identify the correct IUPAC name of hydrocarbon (x) containing three primary carbon atoms and with molar mass 72 g mol$^{-1}$.

The total number of unpaired electrons present in the $d^3$, $d^4$ (low spin), $d^5$ (high spin), $d^6$ (high spin) and $d^7$ (low spin) octahedral complex systems is ______.

Identify the incorrect statement about tertiary structure of proteins.

Identify the correct statements from the following
A. $[Fe(C_2O_4)_3]^{3-}$ is the most stable complex among $[Fe(OH)_6]^{3-}$, $[Fe(C_2O_4)_3]^{3-}$ and $[Fe(SCN)_6]^{3-}$
B. The stability of $[Cu(NH_3)_4]^{2+}$ is greater than that of $[Cu(en)_2]^{2+}$
C. The hybridization of Fe in $K_4[Fe(CN)_6]$ is $d^2sp^3$
D. $[Fe(NO_2)_3Cl_3]^{3-}$ exhibits linkage isomerism
E. $NO_2^-$ and $SCN^-$ ligands are NOT ambidentate ligands
Choose the correct answer from the options given below :

The correct order of molar heat capacities measured at 298 K and 1 bar is :

Given below are two statements :
Statement I : Heating benzamide with bromine in an ethanolic solution of sodium hydroxide will give benzylamine.
Statement II : Nitration of aniline with $HNO_3/H_2SO_4$ at 288 K produces m-nitroaniline in higher amount than o-nitroaniline (pH adjusted).
In the light of the above statements, choose the correct answer from the options given below :

The covalent radii of atoms A and B are $r_A$ and $r_B$, respectively. The covalent bond length and total length of AB molecule are respectively :

At 298 K, the molar conductivity of $x% \ (w/w)$ MX solution (aqueous) is 123.5 S cm$^2$ mol$^{-1}$. The conductance of same solution is $1.9 \times 10^{-3}$ S. The value of $x$ is ______ $\times 10^{-2}$.
(Given : cell constant $= 1.3 \text{ cm}^{-1}$; molar mass of MX is 75 g mol$^{-1}$, density of aqueous solution of MX at 298 K is 1.0 g mL$^{-1}$)}

IUPAC name of the some alkenes are given below. Find out the correct stability order.
A. 2-Methylbut-2-ene
B. cis-But-2-ene
C. 2,3-Dimethylbut-2-ene
D. Prop-1-ene
Choose the correct answer from the options given below :

Match List - I with List - II.

Choose the correct answer from the options given below :

Which of the following statement(s) is/are true?
A. If two orbitals have the same value of $(n+l)$, the orbital with lower value of $n$ will have lower energy.
B. Energies of the orbitals in the same subshell increase with increase in atomic number.
C. The size of $2p_x$ orbital is less than the size of $3p_x$ orbital.
D. Among 5f, 6s, 4d, 5p and 5d orbitals, none of the orbitals have 2 radial nodes.
Choose the correct answer from the options given below :

Complete the following reaction sequence and give the name of major product 'P'.

$2.8 \times 10^{-3}$ mol of CO$_2$ is left after removing $10^{21}$ molecules from its $x$ mg sample. The mass of CO$_2$ taken initially is: Given: $N_A = 6.02 \times 10^{23}\,\text{mol}^{-1}$

Which of the following compounds shows coordination isomerism?
(A) \( [\text{Fe(NH}_3)_6] [\text{Co(CN)}_6] \)
(B) \( [\text{Cr(NH}_3)_6] [\text{Co(CN)}_6] \)
(C) \( [\text{Co(NH}_3)_6] [\text{Co(CN)}_6] \)
(D) \( [\text{Ag(NH}_3)_2] [\text{Ag(CN)}_2] \)
(E) \( [\text{Fe(NH}_3)_6] [\text{Cr(CN)}_6] \)