List of top Chemistry Questions asked in JEE Main

Consider the ions/molecules \(O^{2+}, O_2, O_2^-, O_2^{2-}\)For increasing bond order the correct option is
Match List-I with List-II
List-I (Processes/ Reactions)List-II (Catalyst)
(A) \(2SO_2(g) + O_2(g)\)(I) \(\underrightarrow {Fe(s)}\ \  2SO_3(g)\)
(B) \(4NH_3(g) + 5O_2(g)\)(II) \(\underrightarrow {Pt(s) – Rh(s)}\ \  4NO(g) + 6H_2O(g)\)
(C) \(N_2(g) + 3H_2(g)\)(III) \(\underrightarrow {V_2O_5}\ \  2NH_3(g)\)
(D) Vegetable oil \((l)+ H_2\)(IV) \(\underrightarrow {Ni(s)}\)  Vegetable ghee(s)
Choose the correct answer from the options given below:
Spin only magnetic moment of [MnBr6]4– is _____B.M. [round off to the closest integer]
The spin only magnetic moment of the complex present in Fehling’s reagent is_____ B.M. (Nearest integer).
Correct structure of γ-methylcyclohexane carbaldehyde is
Fig. Chemical Reaction







Consider the above reaction sequence and identify the product B.

For a real gas at 25°C temperature and high pressure (99 bar) the value of the compressibility factor is 2, so the value of van der Waal’s constant ‘b’ should be ______ × 10–2 L mol–1 (Nearest integer).
(Given R=0.083 L bar K-1 mol-1)
The first ionization enthalpy of Na, Mg and Si, respectively, are : 496, 737 and 786 kJ mol–1. The first ionization enthalpy (kJ mol–1) of Al is:
Match List I with List II.
List I
Pollutant		List II
Source
A. MicroorganismsI. Strip mining
B. Plant nutrientsII. Domestic sewage
C. Toxic heavy metalsIII. Chemical fertilizer
D. SedimentIV. Chemical factory

Choose the correct answer from the options given below:

Fig.

 

 

 



In the above reaction ‘A’ is

In \(3d\) series, the metal having the highest \(M^{2+}/M\) standard electrode potential is

A compound ‘X’ is acidic and it is soluble in NaOH solution, but insoluble in NaHCO3 solution. Compound ‘X’ also gives violet colour with neutral FeCl3 solution. The compound ‘X’ is :
 

Given below are two statements :
Statement I : The pentavalent oxide of group-15 element, E2O5, is less acidic than trivalent oxide, E2O3, of the same element.
Statement II : The acidic character of trivalent oxide of group 15 elements, E2O3, decreases down the group.
In light of the above statements, choose most appropriate answer from the options given below:
An acidified manganate solution undergoes disproportionation reaction. The spin-only magnetic moment value of the product having manganese in higher oxidation state is ____ B.M. (Nearest integer)
Elevation in boiling point for 1.5 molal solution of glucose in water is 4 K. The depression in freezing point for 4.5 molal solution of glucose in water is 4 K. The ratio of molal elevation constant to molal depression constant (Kb/Kf) is ___.
Which one of the following is an example of artificial sweetner?

An organic compound ‘A’ on reaction with NH3 followed by heating gives compound B. Which on further strong heating gives compound C(C8H5NO2). Compound C on sequential reaction with ethanolic KOH, alkyl chloride and hydrolysis with alkali gives a primary amine. The compound A is :

Nitrogen gas is obtained by thermal decomposition of
An evacuated glass vessel weighs 40.0 g when empty, 135.0 g when filled with a liquid of density 0.95 g mL–1 and 40.5 g when filled with an ideal gas at 0.82 atm at 250 K. The molar mass of the gas in g mol–1 is: (Given : R = 0.082 L atm K–1 mol–1)

Consider the following reactions. 

\(PCl_3+H_2→A+HCL\)

\(A+H_2o→B+HCL\)

The number of ionisable protons present in the product B is

Match List-I with List-II
List-I
(A) Spontaneous process
(B) Process with \(ΔP = 0\), \(ΔT = 0\)
(C) \(ΔH_{reaction}\)
(D) Exothermic Process
List-II
(I) \(ΔH < 0\)
(II) \(ΔG_{T,P} < 0\)
(III) Isothermal and isobaric process
(IV) [Bond energies of molecules in reactants] – [Bond energies of product molecules]
Choose the correct answer from the options given below :
The major product in the reaction is:
The major product in the reaction with product2-Methyl prop-1-ene
Optical activity of an enantiomeric mixture is +12.6° and the specific rotation of (+) isomer is +30°. The optical purity is _______%.
Resistance of a conductivity cell (cell constant 129 m–1) filled with 74.5 ppm solution of KCI is 100 Ω (labelled as solution 1). When the same cell is filled with KCl solution of 149 ppm, the resistance is 50 Ω (labelled as solution 2). The ratio of molar conductivity of solution 1 and solution 2 is \(\frac{\Lambda_1}{\Lambda_2} = x \times 10^{-3}\). The value of x is _________. (Nearest integer)
(Given : molar mass of KCl is 74.5 g mol–1).
Given below are two statements:
Statement I: In ‘Lassaigne’s Test’, when both nitrogen and sulphur are present in an organic compound, sodium thiocyanate is formed.
Statement II: If both nitrogen and sulphur are present in an organic compound, then the excess of
sodium used in sodium fusion will decompose the sodium thiocyanate formed to give NaCN and Na2S.
In the light of the above statements, choose the most appropriate answer from the options given below: