List of top Chemistry Questions asked in JEE Main

Which of the following compound does not contain sulphur atom?

A student needs to prepare a buffer solution of propanoic acid and its sodium salt with pH 4. The ratio of
\(\frac{[CH_3CH_2COO^−]}{[CH_3CH_2COOH] }\)
required to make buffer is _____.
Given : K_a(CH₃CH₂COOH) = 1.3 × 10^–5

0.25 g of an organic compound containing chlorine gave 0.40 g of silver chloride in Carius estimation. The percentage of chlorine present in the compound is ______. [in nearest integer]
(Given : Molar mass of \(Ag\) is 108 g mol^–1 and that of \(Cl\) is 35.5 g mol^–1

For combustion of one mole of magnesium in an open container at 300K and 1bar pressure, Δ_CH^Θ=–601.70kJ mol^–1, the magnitude of change in internal energy for the reaction is______ kJ. (Nearest integer) (Given : R = 8.3 J K^–1 mol^–1)

If the initial pressure of a gas 0.03 atm, the mass of the gas absorbed per gram of the adsorbent is ____× 10^–2g

In isolation of which one of the following metals from their ores, the use of cyanide salt is not commonly involved?

Which of the following is most stable?

Using the rules for significant figures, the correct answer for the expression
\(\frac{0.02858 × 0.112}{ 0.5702}\)
will be

The \(\left(\frac{\partial E}{\partial T}\right)_p\) of different types of half cells are as follows:

A	B	C	D
1 × 10^-4	2 × 10^-4	0.1 × 10^-4	0.2 × 10^-4

(Where E is the electromotive force)
Which of the above half cells would be preferred to be used as reference electrode?

The correct order of increasing ionic radii is

A solution containing 2.5 × 10^–3 kg of a solute dissolved in 75 × 10^–3 kg of water boils at 373.535 K. The molar mass of the solute is _____ g mol^–1. [nearest integer] (Given : K_b(H₂O) = 0.52 K kg mol^–1 and boiling point of water = 373.15 K)

The cell potential for \(\text{Zn}|\text{Zn}^{2+}\text{(aq)}||\text{Sn}^{x+}|\text{Sn}\) is 0.801 V at 298 K.The reaction quotient for the above reaction is 10^–2. The number of electrons involved in the given electrochemical cell reaction is _____. (Given: \(Eº_Zn^{2+}\)|Zn=-0.763V,Eºsn^x+|sn=+0.008V and 2.303RT/F=0.06V)

Compound ‘P’ on nitration with dil. HNO₃ yields two isomers (A) and (B) show the intramolecular and intermolecular hydrogen bonding respectively. Compound (P) on reaction with conc. HNO₃yields a yellow compound ‘C’, a strong acid. The number of oxygen atoms is present in compound ‘C’ _____

L-isomer of a compound ‘A’ \((C_4H_8O_4)\) gives a positive test with \([Ag(NH_3)^2]^+\). Treatment of ‘A’ with acetic anhydride yields triacetate derivative. Compound ‘A’ produces an optically active compound (B) and an optically inactive compound (C) on treatment with bromine water and \(HNO_3\) respectively. Compound (A) is:

If the radius of the 3^rd Bohr’s orbit of hydrogen atom is r₃ and the radius of 4^th Bohr’s orbit is r₄. Then

Incorrect statement for Tyndall effect is:

While estimating the nitrogen present in an organic compound by Kjeldahl’s method, the ammonia evolved from 0.25g of the compound neutralized 2.5mL of 2M H₂SO₄. The percentage of nitrogen present in organic compound is ________

Most stable product of the following reaction is :

Drugs used to bind to receptors, inhibiting its natural function and blocking a message are called:

Choose the correct order of density of the alkali metals.

Which of the following sets of quantum numbers is not allowed?

The compound(s) that is(are) removed as slag during the extraction of copper is
(A)CaO,(B)FeO,(C)Al₂O₃,(D)ZnO,(E)NiO
Choose the correct answer from the options given below :

During the denaturation of proteins, which of these structures will remain intact?

The interhalogen compound formed from the reaction of bromine with excess of fluorine is a :

Consider the following metal complexes:
[Co(NH₃)₆]³⁺[CoCl(NH₃)₅]²⁺[Co(CN)₆]^3–[Co(NH₃)₅(H₂O)]³⁺The spin-only magnetic moment value of the complex that absorbs light with shortest wavelength is _______ B.M. (Nearest integer)