List of top Chemistry Questions asked in JEE Main

The depression in the freezing point observed for a formic acid solution of concentration 0.5 mL L^–1 is 0.0405°C. Density of formic acid is 1.05 g mL^–1. The Van’t Hoff factor of the formic acid solution is nearly (Given for water k_f = 1.86 k kg mol^–1)

20 mL of 0.1 M NH₄OH is mixed with 40 mL of 0.05 M HCl.The pH of the mixture is nearest to(Given :K_b(NH₄OH) = 1×10^–5,log2 = 0.30,log3 = 0.48, log5 = 0.69,log7 = 0.84,log11 = 1.04)

Match List-I with List-II.

List-I	List-II
(A) N₂(g) + 3H₂(g) → 2NH₃(g)	(I) Cu
(B) CO(g) + 3H₂(g) → CH₄(g) + H₂O(g)	(II) Cu/ZnO – Cr₂O₃
(C) CO(g) + H₂(g) → HCHO(g)	(III) Fe_xO_y + K₂O + Al₂O₃
(D) CO(g) + 2H₂(g) → CH₃OH(g)	(IV) Ni

Choose the correct answer from the options given below :

The IUPAC nomenclature of an element with electronic configuration [Rn] 5f¹⁴6d¹7s² is

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 :

Choose the correct order of density of the alkali metals.

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

Most stable product of the following reaction is :

Which one of the following reactions does not represent correct combination of substrateand product under the given conditions?

Melamine polymer is formed by the condensation of :

Given below are two statements:
Statement I: On heating with KHSO₄, glycerol is dehydrated and acrolein is formed.
Statement II: Acrolein has fruity odour and can be used to test glycerol’s presence.
Choose the correct option

Among the following species
N₂,N₂⁺,N₂⁻,N₂²⁻,O₂,O₂⁺,O₂⁻,O₂²⁻
the number of species showing diamagnetism is ________.

The enthalpy of combustion of propane, graphite and dihydrogen at 298 K are –2220.0 kJ mol^–1, –393.5 kJ mol^–1 and –285.8 kJ mol^–1, respectively. The magnitude of enthalpy of formation of propane (C₃H₈) is _____ kJ mol^–1. (Nearest integer)

The pressure of a moist gas at 27°C is 4 atm. The volume of the container is doubled at the same temperature. The new pressure of the moist gas is ______ ×10^–1 atm. (Nearest integer)(Given: The vapor pressure of water at 27°C is 0.4 atm.)

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)

The half-life for the decomposition of gaseous compound A is 240 s when the gaseous pressure was 500 torr initially. When the pressure was 250 torr, the half-life was found to be 4.0 min. The order of the reaction is ______. (Nearest integer)

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)

Among Co³⁺, Ti²⁺, V²⁺ and Cr²⁺ions, one if used as a reagent cannot liberate H₂ from dilute mineral acid solution, its spin-only magnetic moment in gaseous state is________ B.M. (Nearest integer)

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

The number of sp³ hybridised carbons in an acyclic neutral compound with molecular formula C₄H₅N is ________.

In the given reaction,