List of top Chemistry Questions asked in JEE Main

Most suitable salt which can be used for efficient clotting of blood will be :

Assertion A : Hydrogen is the most abundant element in the Universe, but it is not the most abundant gas in the troposphere. Reason R : Hydrogen is the lightest element.

According to Bohr's atomic theory : (A) Kinetic energy of electron is $\propto Z^2 / n^2$. (B) The product of velocity (v) of electron and principal quantum number (n), 'vn' $\propto Z^2$. (C) Frequency of revolution of electron in an orbit is $\propto Z^2 / n^3$. (D) Coulombic force of attraction on the electron is $\propto Z^3 / n^4$. Choose the most appropriate answer :

Considering the reaction of Benzene with CO and HCl in the presence of anhydrous AlCl₃/CuCl (Gattermann-Koch reaction), identify product X :

Considering the hydrolysis of Benzonitrile ($C_6H_5CN$) in acidic medium (H₂O/H⁺), identify the product A :

Reaction of Grignard reagent, C₂H₅MgBr with C₈H₈O followed by hydrolysis gives compound "A" which reacts instantly with Lucas reagent to give compound B, C₁₀H₁₃Cl. The Compound B is :

In order to prepare a buffer solution of pH 5.74, sodium acetate is added to acetic acid. If the concentration of acetic acid in the buffer is 1.0 M, the concentration of sodium acetate in the buffer is __________ M. (Round off to the Nearest Integer). [Given : pKa (acetic acid) = 4.74]

Complete combustion of 3 g of ethane gives x × 10$^{22}$ molecules of water. The value of x is _________. (Round off to the Nearest Integer). [Use : $N_A$ = 6.023 × 10$^{23}$; Atomic masses in u : C : 12.0 ; O : 16.0 ; H : 1.0]

Match List - I with List - II : List - I (Class of Drug)
(a) Antacid
(b) Artificial Sweetener
(c) Antifertility
(d) Tranquilizers List - II (Example)
(i) Novestrol
(ii) Cimetidine
(iii) Valium
(iv) Alitame

Reagent, 1-naphthylamine and sulphanilic acid in acetic acid is used for the detection of :

The statements that are TRUE : (A) methane leads to both global warming and photochemical smog (B) methane is generated from paddy fields (C) methane is a stronger global warming gas than CO₂ (D) methane is a part of reducing smog. Choose the most appropriate answer from the options given below :

The chemical that is added to reduce the melting point of the reaction mixture during the extraction of aluminium is :

Match List - I with List - II : List - I
(a) Ca(OCl)₂
(b) CaSO₄ · 1/2 H₂O
(c) CaO
(d) CaCO₃ List - II
(i) Antacid
(ii) Cement
(iii) Bleach
(iv) Plaster of Paris

Assertion A : During the boiling of water having temporary hardness, Mg(HCO₃)₂ is converted to MgCO₃.
Reason R : The solubility product of Mg(OH)₂ is greater than that of MgCO₃.

The number of ionisable hydrogens present in the product obtained from a reaction of phosphorus trichloride and phosphonic acid is :

Match List - I with List - II : List - I (Process)
(a) Deacon's process
(b) Contact process
(c) Cracking of hydrocarbons
(d) Hydrogenation of vegetable oils List - II (Catalyst)
(i) ZSM-5
(ii) CuCl₂
(iii) Particles 'Ni'
(iv) V₂O₅

The ionic radius of Na⁺ ion is 1.02 Å. The ionic radii (in Å) of Mg²⁺ and Al³⁺, respectively, are :

In a binary compound, atoms of element A form a hcp structure and those of element M occupy 2/3 of the tetrahedral voids of the hcp structure. The formula of the binary compound is :

A certain orbital has no angular nodes and two radial nodes. The orbital is :

Which one of the following compounds will liberate $CO_2$ when treated with $NaHCO_3$?

The given reaction can occur in the presence of:

(a) Bromine water
(b) $Br_2$ in $CS_2$, 273 K
(c) $Br_2/FeBr_3$
(d) $Br_2$ in $CHCl_3$, 273 K
Choose the correct answer from the options given below:

Consider the complete combustion of butane, the amount of butane utilized to produce 72.0 g of water is ________ $\times 10^{-1}$ g. (in nearest integer)

A home owner uses $4.00 \times 10^3 \text{ m}^3$ of methane ($CH_4$) gas, (assume $CH_4$ is an ideal gas) in a year to heat his home. Under the pressure of 1.0 atm and 300 K, mass of gas used is $x \times 10^5$ g. The value of $x$ is ________. (Nearest integer) (Given R = 0.083 L atm $K^{-1} mol^{-1}$)

For the reaction $A + B \rightleftharpoons 2C$ the value of equilibrium constant is 100 at 298 K. If the initial concentration of all the three species is 1 M each, then the equilibrium concentration of C is $x \times 10^{-1}$ M. The value of $x$ is ________. (Nearest integer)