List of top Chemistry Questions asked in JEE Main

The total number of carbon atoms present in tyrosine, an amino acid, is _______.

Match List-I with List-II.

List-I (Complex ion)	List-II (Spin only magnetic moment in B.M.)
(A) [Cr(NH$_3$)$_6$]$^{3+}$	(I) 4.90
(B) [NiCl$_4$]$^{2-}$	(II) 3.87
(C) [CoF$_6$]$^{3-}$	(III) 0.0
(D) [Ni(CN)$_4$]$^{2-}$	(IV) 2.83

Choose the correct answer from the options given below:

The correct sequence of acidic strength of the following aliphatic acids in their decreasing order is: $CH_3CH_2COOH$, $CH_3COOH$, $CH_3CH_2CH_2COOH$, $HCOOH$

$\Delta_{vap}H^\circ$ for water is $+40.49 \, \text{kJ mol}^{-1}$ at 1 bar and $100^\circ\text{C}$. Change in internal energy for this vaporisation under same condition is .............. kJ mol$^{-1}$. (Integer answer)
(Given R = 8.3 J K$^{-1}$ mol$^{-1}$)

Wavenumber for a radiation having $5800 \, \mathring{A}$ wavelength is $x \times 10 \, \text{cm}^{-1}$. The value of $x$ is _________

Total number of optically active compounds from the following is _______.

Given below are two statements: One is labelled as Assertion A and the other is labelled as Reason R:
Assertion A: The stability order of \(+1\) oxidation state of Ga, In, and Tl is \( \text{Ga}<\text{In}<\text{Tl} \).
Reason R: The inert pair effect stabilizes the lower oxidation state down the group.
In the light of the above statements, choose the correct answer from the options given below:

Total number of aromatic compounds among the following compounds is _______.

Match List-I with List-II.

List-I (Name of the test)	List-II (Reaction sequence involved) [M is metal]
(A) Borax bead test	I
(B) Charcoal cavity test	II
(C) Cobalt nitrate test	III
(D) Flame test	IV

Choose the correct answer from the options given below:

Given below are two statements :
Statement (I) : Kjeldahl method is applicable to estimate nitrogen in pyridine.
Statement (II) : The nitrogen present in pyridine can easily be converted into ammonium sulphate in Kjeldahl method.
In the light of the above statements, choose the correct answer from the options given below.

Which among the following compounds will undergo fastest \(S_N2\) reaction?

Given below are two statements:
Statement I:

IUPAC name of Compound A is 4-chloro-1, 3-dinitrobenzene.
Statement II:

IUPAC name of Compound B is 4-ethyl-2-methylaniline.
In the light of the above statements, choose the most appropriate answer from the options given below:

Molality of an aqueous solution of urea is 4.44 m. Mole fraction of urea in solution is x × 10^–3. Value of x is _______. (integer answer)

A solution is prepared by adding 1 mole ethyl alcohol in 9 mole water. The mass percent of solute in the solution is ___________ (Integer Answer)
(Given : Molar mass in g mol$^{-1}$ Ethyl alcohol : 46, water : 18)

Given below are two statements:
Statement (I) : A Buffer solution is the mixture of a salt and an acid or a base mixed in any particular quantities.
Statement (II) : Blood is naturally occurring buffer solution whose pH is maintained by $H_2CO_3/HCO_3^-$ concentrations.
In the light of the above statements, choose the correct answer from the options given below.

Number of complexes with even number of electrons in \(t_{2g}\) orbitals is: \[[\text{Fe(H}_2\text{O)}_6]^{2+}, \, [\text{Co(H}_2\text{O)}_6]^{2+}, \, [\text{Co(H}_2\text{O)}_6]^{3+}, \, [\text{Cu(H}_2\text{O)}_6]^{2+}, \, [\text{Cr(H}_2\text{O)}_6]^{2+}\]

The 'spin only' magnetic moment value of \(MO_4^{2-}\) is ____ \(\text{BM}\). (Where \(M\) is a metal having least metallic radii among \(\text{Sc, Ti, V, Cr, Mn, Zn}\)). \([ \text{Given atomic number: Sc = 21, Ti = 22, V = 23, Cr = 24, Mn = 25, Zn = 30} ]\)

The equilibrium constant for the reaction
\( \text{SO}_3 \, (g) \rightleftharpoons \text{SO}_2 \, (g) + \frac{1}{2} \text{O}_2 \, (g) \)
is \( K_C = 4.9 \times 10^{-2} \). The value of \( K_C \) for the reaction given below is
\( 2 \text{SO}_2 \, (g) + \text{O}_2 \, (g) \rightleftharpoons 2 \text{SO}_3 \, (g) \) is

The number of optical isomers in following compound is : _____.

Given below are two statements:
Statement I: \(N(CH_3)_3\) and \(P(CH_3)_3\) can act as ligands to form transition metal complexes.
Statement II: As \(N\) and \(P\) are from the same group, the nature of bonding of \(N(CH_3)_3\) and \(P(CH_3)_3\) is always the same with transition metals.
In the light of the above statements, choose the most appropriate answer from the options given below:

In the given compound, the number of 2° carbon atom/s is _____.

Match List-I with List-II

List-I (Compound)	List-II (Colour)
(A) \(Fe_4[Fe(CN)_6]_3.xH_2O\)	(I) Violet
(B) \( [Fe(CN)_5NOS]^{4–} \)	(II) Blood Red
(C) \( [Fe(SCN)]^{2+}\)	(III) Prussian Blue
(D) \((NH_4)_3PO_4.12MoO_3\)	(IV) Yellow

Choose the correct answer from the options given below:

Match List-I with List-II.

List-I (Elements)	List-II (Properties in their respective groups)
(A) Cl,S	(I) Elements with highest electronegativity
(B) Ge, As	(II) Elements with largest atomic size
(C) Fr, Ra	(III) Elements which show properties of both metals and non metal
(D) F, O	(IV) Elements with highest negative electron gain enthalpy

Choose the correct answer from the options given below:

Consider the figure provided. 1 mol of an ideal gas is kept in a cylinder, fitted with a piston, at the position A, at \(18^\circ \text{C}\). If the piston is moved to position B, keeping the temperature unchanged, then 'x' \(\text{L atm}\) work is done in this reversible process. \(x =\) ______ \(\text{L atm}\). (nearest integer)
\([ \text{Given: Absolute temperature} = ^\circ \text{C} + 273.15, \, R = 0.08206 \, \text{L atm mol}^{-1} \text{K}^{-1} ]\)

Match List-I with List-II.

List-I (Molecule)	List-II (Shape)
(A) \(NH_3\)	(I) Square pyramid
(B) \(BrF_5\)	(II) Tetrahedral
(C) \(PCL_5\)	(III) Trigonal pyramidal
(D) \(CH_4\)	(IV) Trigonal bipyramidal

Choose the correct answer from the options given below: