List of top Chemistry Questions asked in JEE Main

Which of the following chemical reactions represents Hall-Heroult Process?
In the industrial production of which of the following, molecular hydrogen is obtained as a byproduct?

The number of bridged oxygen atoms present in compound B formed from the following reactions is 

\(PB(NO_3)^2→(673 K)→A+PBO+O_2A→(Dimerise)B.\)

In the following structures, which one is having staggered conformation with maximum dihedral angle?

Given below are two statements one is labelled as Assertion A and the other is labelled as Reason R:

Assertion A: The amphoteric nature of water is explained by using Lewis acid/base concept

Reason R: Water acts as an acid with NH3 and as a base with H2S.

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

The energy of one mole of photons of radiation of wavelength \(300\) \(nm\) is (Given \(h\) = \(6.63 × 10^{–34}\)Js, \(N_A\) = \(6.02 × 10^{23}\) \(mol^{–1}\), \(c = 3 × 10^8\) \(ms^{–1}\))
The correct order of electron gain enthalpies of Cl, F, Te and Po is

Choose the correct answer :

1. The minimum energy that must be possessed by photons in order to produce the photoelectric effect with platinum metal is

[Given The threshold frequency of platinum is 1.3 × 1015 s–1 and h = 6.6 × 10–34 Js.]

Using very little soap while washing clothes, does not serve the purpose of cleaning of clothes, because:
Metals generally melt at very high temperature. Amongst the following, the metal with the highest melting point will be
The Ksp for bismuth sulphide (Bi2S3) is 1.08 × 10–73. The solubility of Bi2S3 in mol L–1 at 298 K is
\(PCl_5\) is well known, but \(NCl_5\) is not. Because,

Given below are two statements: one is labelled as Assertion A and the other is labelled as Reason R.

Assertion A: Polluted water may have a value of BOD of the order of 17 ppm.

Reason R: BOD is a measure of oxygen required to oxidise both the bio-degradable and non-biodegradable organic material in water.

In the light of the above statements, choose the most appropriate answer from the options given below.

Which one of the following compounds is used as a chemical in certain type of fire extinguishers?
Which one of the following is an example of artificial sweetner?
A compound ‘X’ is a weak acid and it exhibits colour change at pH close to the equivalence point during neutralization of NaOH with CH3COOH. Compound ‘X’ exists in ionized from in basic medium. The compound ‘X’ is

Given below are the critical temperatures of some of the gases :

GasCritical temperature (K)
He5.2
CH4190.0
CO2304.2
NH3405.5

The gas showing least adsorption on a definite amount of charcoal is

Octahedral complexes of copper(II) undergo structural distortion (Jahn-Teller). Which one of the given copper(II) complexes will show the maximum structural distortion?
(en – ethylenediamine;H2N−CH2−CH2−NH2)
Given below are two statements.
Statement I: The compound
The compound
(A) is optically active.
Statement II:
mirror image of above compound
is a mirror image of the above compound A.
In the light of the above statement, choose the most appropriate answer from the options given below.
Correct structure of γ-methylcyclohexane carbaldehyde is
In liquation process used for tin (Sn), the metal
Which of the following 3d-metal ion will give the lowest enthalpy of hydration (ΔhydH) when dissolved in water?
Consider the reaction
\(4\text{HNO}_3(\text{l}) + 3\text{KCl}(\text{s}) \rightarrow \text{Cl}_2(\text{g}) + \text{NOCl}(\text{g}) + 2\text{H}_2\text{O}(\text{g}) + 3\text{KNO}_3(\text{s})\)
The amount of HNO3 required to produce 110.0 g of KNO3 is
(Given : Atomic masses of H, O, N and K are 1, 16, 14 and 39 respectively.)
200 mL of 0.01 M HCl is mixed with 400 mL of 0.01 M H2SO4. The pH of the mixture is ___.
[Given log 2 = 0.30, log 3 = 0. 48, log 5 = 0.70, log7 = 0.84, log 11 = 1.04.]
Given below are two statements. One is labelled as Assertion A and the other is labelled as Reason R.
Assertion A : Amylose is insoluble in water.
Reason R : Amylose is a long linear molecule with more than 200 glucose units.
In the light of the above statements, choose the correct answer from the options given below.