List of top Chemistry Questions asked in JEE Main

A box contains 0.90 g of liquid water in equilibrium with water vapour at 27°C. The equilibrium vapour pressure of water at 27°C is 32.0 Torr. When the volume of the box is increased, some of the liquid water evaporates to maintain the equilibrium pressure. 
If all the liquid water evaporates, then the volume of the box must be ______ litre. [nearest integer]
(Given : R = 0.082 L atm K–1 mol–1] (Ignore the volume of the liquid water and assume water vapours behave as an ideal gas.)
When 200 mL of 0.2 M acetic acid is shaken with 0.6 g of wood charcoal, the final concentration of acetic acid after adsorption is 0.1 M. The mass of acetic acid adsorbed per gram of carbon is _____ g.

Match List-I with List-II
 

List-IList-II
(A) Glucose + HI(I) Gluconic acid
(B) Glucose + Br2 water(II) Glucose pentacetate
(C) Glucose + acetic anhydride(III) Saccharic acid
(D) Glucose + HNO3(IV) Hexane
The structure of protein that is unaffected by heating is
Which will have the highest enol content?
The plot of pH-metric titration of weak base NH4OH vs strong acid HCl looks lie:

Given below are two statements:

Statement I: [Ni(CN)4]2– is square planar and diamagnetic complex, with dsp2 hybridization for Ni but [Ni(CO)4] is tetrahedral, paramagnetic and with sp3-hybridization for Ni.
Statement II: [NiCl4]2– and [Ni(CO)4] both have same d-electron configuration, have same geometry and are paramagnetic.

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

In the flame test of a mixture of salts, a green flame with blue centre was observed. Which one of the following cations may be present?
At \(298\ K\), the equilibrium constant is \(2 × 10^{15}\) for the reaction:
\(Cu(s)+2Ag+(Aq)⇌Cu^{2+}(aq)+2Ag(s)\)
The equilibrium constant for the reaction:
\(\frac 12Cu^{2+}(aq)+Ag(s)+(Aq)⇌\frac 12Cu(s)+Ag^+(aq)\) is \(x \times10^{-8}\).
The value of \(x\) is ______ . (Nearest integer)
Which statement is NOT correct for p-toluenesulphonyl chloride?
White phosphorus reacts with thionyl chloride to give
The solubility product of a sparingly soluble salt \(A_2X_3\) is \(1.1 × 10^{–23}\). If the specific conductance of the solution is \(3×10^{–5}\) S m–1, the limiting molar conductivity of the solution is \(x×10^{–3}\) S m2 mol–1. The value of x is _______.
Which one of the lanthanoids given below is the most stable in divalent form?
The structure shown below is of which well-known drug molecule?
drug molecule
Stability of α-Helix structure of proteins depends upon
Match List-I with List -II
List - IList - II
(A) \(ψ_{MO}=ψ_A-ψ_B\)(I) Dipole moment
(B) \(µ=Q×r \)(II) Bonding molecular orbital
(C) \(\frac{N_b-N_a}2\)(III) Anti-bonding molecular orbital
(D) \(ψ_{MO}=ψ_A+ψ_B\)(IV) Bond order

Choose the correct answer from options given below:

Consider the following statements :
(A) The principal quantum number ‘n’ is a positive integer with values of ‘n’ = 1, 2, 3, ….
(B) The azimuthal quantum number ‘l’ for a given ‘n’ (principal quantum number) can have values as ‘l’ = 0, 1, 2, …n
(C) Magnetic orbital quantum number ‘ml’ for a particular ‘l’ (azimuthal quantum number) has (2l + 1) values.
(D) ±1/2 are the two possible orientations of electron spin.
(E) For l = 5, there will be a total of 9 orbital
Which of the above statements are correct?

The resistance of a conductivity cell containing \(0.01\) M KCl solution at \(298\ K\) is \(1750\ Ω\). If the conductivity of \(0.01\) M KCl solution at \(298\ K\) is \(0.152×10^{–3}\) S cm–1, then the cell constant of the conductivity cell is ______ \(×10^{–3}\) cm–1.
Match List I with List II.
 List I (Anion) List II (gas evolved on reaction with dil \(H_2SO_4\))
A.\(CO_3^{ 2−}\)I.Colourless gas which turns lead acetate paper black.
B.\(S^{2–}\)II.Colourless gas which turns acidified potassium dichromate solution green
C.\(SO_3^{ 2−}\)III.Brown fumes which turns acidified KI solution containing starch blue.
D.\(NO_2^{−}\)IV.Colourless gas evolved with brisk effervescence, which turns lime water milky.
Choose the correct answer from the options given below:

Match List-I with List-II
 

 List-I Ore List-II Composition
A.SideriteI.FeCO3
B.MalachiteII.CuCO3. Cu(OH)2
C.SphaleriteIII.ZnS
D.CalamineIV.ZnCO3


Choose the correct answer from the options given below:

Which of the following is not an example of a condensation polymer?
Dihydrogen reacts with CuO to give
Given below are two statements: One is labelled as Assertion A and the other is labelled as Reason R 
Assertion A: Zero orbital overlap is an out of phase overlap. 
Reason R: It results due to different orientation/direction of approach of orbitals. 
In the light of the above statements, choose the correct answer from the options given below
Amongst the following, the number of oxide(s) which are paramagnetic in nature is
Na2O, KO2, NO2, N2O, ClO2, NO, SO2, Cl2O
A mixture of hydrogen and oxygen contains 40% hydrogen by mass when the pressure is 2.2 bar. The partial pressure of hydrogen is _______ bar. (Nearest integer)