List of top Chemistry Questions asked in JEE Main

The element playing significant role in neuromuscular function and interneuronal transmission is :

Which of the following elements have half-filled f-orbitals in their ground state?
(Given : atomic number $Sm =62 ; Eu =63 ; Tb =65 ; Gd =64, Pm =61$ )
A. $Sm$
B. $Eu$
C. $Tb$
D. $Gd$
E. $Pm$
Choose the correct answer from the options given below :

Boric acid is solid, whereas $BF _3$ is gas at room temperature because of

Graph of X-ray frequency (v)n v/s atomic number (Z) is linear. Find the value of n.

The starting material for convenient preparation of deuterated hydrogen peroxide \(\left(D_2 O _2\right)\) in laboratory is :

\([Co(NH_3)_6]^{3+} \text{is} \) ________\(\text{hybridised and}\)________

Given below are two statements:
Statement-I: Pure Aniline and other arylamines are usually colourless.
Statement-II: Arylamines get coloured on storage due to atmospheric reduction
In the light of the above statements, choose the most appropriate answer from the options given below:

Find correct order of covalent character (A) \(KF < KI\) (B) \(CuCl > NaCl\) (C) \(LiF > KF\)

Number of unpaired electron in highest occupied molecular orbital of following species is :\(N_2, N ^+_ 2 , O_2, O^+_ 2 \) ? 

Which of the following complex will show largest splitting of $d$-orbitals?
How many reactions are non-spontaneous at 300 K. For independent reaction ΔH & ΔS values are given.
Given below are two statements: one is labelled as Assertion A and the other is labelled as Reason R
Assertion A: In an Ellingham diagram, the oxidation of carbon to carbon monoxide shows a negative slope with respect to temperature
Reason R: CO tends to get decomposed at higher temperature
In the light of the above statements, choose the correct answer from the options given below
An \( \alpha \)-particle, a proton, and an electron have the same kinetic energy. Which one of the following is correct in case of their De-Broglie wavelength:
Freezing point of solution is less than that of pure solvent, which of the following statements are correct ? 
(A) Vapour pressure of solution is less than that of pure solvent 
(B) Vapour pressure of solution is greater than that of pure solvent 
(C) Only solvent molecules will freeze 
(D) Only solute molecules will freeze

Match List I with List II:

LIST I (Type) LIST II (Name)
(P) Antifertility drugs(A) Norethindrone 
(Q) Antihistamines(B) Seldane
(R) Tranquilizers(C) Meprobamate
(S) Antibiotics(D) Penicillin

Choose the correct answer from the options given below:

Match the following:
Column-IColumn-II
(A) Zone refining(P) pig iron
(B) Electrolysis(Q) Al
(C) Reverberatory furnace(R) Si
(D) Blast furnace(S) Cu

Statement-I: Noradrenaline is one of the neurotransmitter. 

Statement-II: Low level of noradrenaline is not cause of depression in humans.

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

In alkaline medium, the reduction of permanganate anion involves a gain of _____ electrons.
The electron in the \(n^{th}\) orbit of \(Li^{2+}\) is excited to \((n + 1)\) orbit using the radiation of energy \(1.47 × 10^{–1}J \) (as shown in the diagrarn). The value of n is ______ .
Given: \(R_H = 2.18 × 10^{–18} J\).
The number of incorrect statement/s from the following is ____ .
A. The successive half lives of zero order reactions decreases with time.
B. A substance appearing as reactant in the chemical equation may not affect the rate of reaction.
C. Order and molecularity of a chemical reaction can be a fractional number.
D. The rate constant units of zero and second order reaction are mol L–1s–1 and mol–1 Ls–1 respectively.
The number of endothermic process/es from the following is _____ .
A. \(I_2 (g) → 2I (g)\)
B. \(HCl (g) → H(g) + Cl (g)\)
C. \(H_2O(l) → H_2O (g)\)
D. \(C(s) + O_2 (g) → CO_2 (g)\)
E. Dissolution of ammonium chloride in water.
The difference in the oxidation state of \(Xe\) between the oxidised product of \(Xe\) formed on complete hydrolysis of \(XeF_4\) and \(XeF_4\) is _____ .
The number of molecules from the following which contain only two lone pair of electrons is _____ .
\(H_2O, N_2, CO, XeF_4, NH_3, NO, CO_2, F_2\)
Ferric chloride is applied to stop bleeding because-
Given below are two statements: one is labelled as Assertion A and the other is labelled as Reason R:
Assertion A: The energy required to form \(Mg^{2+}\) from Mg is much higher than that required to produce \(Mg^+\)
Reason R: \(Mg^{2+}\) is small ion and carry more charge than \(Mg^{+}\).
In the light of the above statements, choose the correct answer from the options given below.