List of top Chemistry Questions asked in JEE Main

The mass of NH3 produced when 131.8 kg of cyclohexanecarbaldehyde undergoes Tollen's test is ___ kg. (Nearest Integer)
Molar Mass of C = 12g/mol 
N = 14g/mol 
0 = 16g/mol

For the adsorption of hydrogen on platinum, the activation energy is 30 kJ mol^-1 and for the adsorption of hydrogen on nickel, the activation energy is 41.4 kJ mol^-1 . The logarithm of the ratio of the rates of chemisorption on equal areas of the metals at 300 K is ……… (Nearest integer) Given: ln 10 = 2. 3  R = 8.3 JK^-1 mol^-1

The number of species from the following which have square pyramidal structure is___\( PF_5, BrF^− _4 4 − , IF_5\) ; \(BrF_5, XeOF_4, ICl ^−_ 4\)

20 mL of calcium hydroxide was consumed when it was reacted with 10 mL of unknown solution of H₂SO4. Also 20 mL standard solution of 0.5 M HCI containing 2 drops of phenolphthalein was titrated with calcium hydroxide the mixture showed pink colour when burette displayed the value of 35.5 mL whereas the burette showed 25.5 mL initially. The concentration of H₂SO₄ is_____M (Nearest integer)

Solution of 12 g of non-electrolyte (A) prepared by dissolving it in 1000 mL of water exerts the same osmotic pressure as that of 0.05 M glucose solution at the same temperature. The empirical formula of A is CH₂O. The molecular mass of A is ____ g. (Nearest integer)

A₂+B₂→2AB. \(ΔH^0_f\)= -200 kJ mol^-1 AB, A2 and B2 are diatomic molecule. If the bond enthalpies of A₂, B₂ and AB are in the ratio 1:0.5:1, then the bond enthalpy of A₂ is ___ kJmol^-1 (Nearest integer)

Number of isomeric aromatic amines with synthesized by Gabriel Phthalimide synthesis molecular formula C₈H₁₁N, which can be is ______. jee main 2023

Among the following, the number of compounds which will give positive iodoform reaction is ____
(a) 1-Phenylbutan-2-one 
(b) 2-Methylbutan-2-ol 
(c) 3-Methylbutan-2-ol 
(d) 1-Phenylethanol 
(e) 3,3-dimethylbutan-2-one 
(f) 1-Phenylpropan-2-ol

In an ice crystal, each water molecule is hydrogen bonded to ___ neighbouring molecules

The standard reduction potential at 298 K for the following half cells are given below  
NO − 3 3 − + 4H+ + 3e- → NO(g) +2H2O E0 = 0.97V 
\(V^{2+} (aq) + 2e^-→V\)           E⁰ = -1.19V 
\(Fe^{3+}(aq) + 3e^- → Fe\)        E⁰ = -0.04V 
\(Ag^+ (aq) + e^- → Ag(s)\)      E⁰ = 0.80V 
\(Au^{3+}(aq)+3e^-→Au(s)\) E⁰ = 1.40V 
The number of metal(s) which will be oxidized by  \(N0^-_3\) Oin aqueous solution is______.

Consider the following pairs of solution which will be isotonic at the same temperature. The number of pairs of solutions is/are......
A. 1 M aq. NaCl and 2 M aq. Urea 
B. 1 M aq. CaCl2 and 1.5 M aq. KCl 
C. 1.5 M aq. AlCl3 and 2 M aq. Na2SO4 
D. 2.5 M aq. KCl and 1 M aq. Al2(SO4)3

The number of species having a square planar shape from the following is __
\(XeF_4, SF_4, SiF_4, BF^-_4 BrF^-_4,[Cu(NH_3)_4]^{2+}, [FeCl_4]^{2-}, [PtCl_4]^{2-}\)

Number of crystal systems from the following where body centred unit cell can be found, is......
Cubic, tetragonal, orthorhombic, hexagonal, rhombohedral, monoclinic, triclinic.

Molar mass of the hydrocarbon (X) which on ozonolysis consumes one mole of O3 per mole of (X) and gives one mole each of ethanal and propanone is _______ g mol-1  
(Molar mass of C : 12 g mol-1 , H : 1 g mol-1)

The titration curve of weak acid vs. strong base with phenolphthalein as indictor is shown below. The K_{phenolphthalein} = 4 × 10^-10 . 
Given: log2 = 0.3

The number of following statements which is/are correct about phenolphthalein is______
A. It can be used as an indicator for the titration of weak acid with weak base.
B. It begins to change colour at pH = 8.4
C. It is a weak organic base
D. It is colourless in acidic medium.

The vapour pressure vs. temperature curve for a solution solvent system is shown below.

The boiling point of the solvent is _____°C.

When a 60 W electric heater is immersed in a gas for 100s in a constant volume container with adiabatic walls, the temperature of the gas rises by 5°C. The heat capacity of the given gas is_____J K^-1 (Nearest integer).

The number of following statement/s which is/are\(\text{\underline{ incorrect}}\) is______  
(A) Line emission spectra are used to study the electronic structure  
(B) The emission spectra of atoms in the gas phase show a continuous spread of wavelength from red to violet  
(C) An absorption spectrum is like the photographic negative of an emission spectrum  
(D) The element helium was discovered in the sun by spectroscopic method.

The homoleptic and octahedral complex of Co²⁺ and H₂O has___ set of orbitals. unpaired electron(s) in the t_2g set of orbitals.

The total change in the oxidation state of manganese involved in the reaction of KMnO₄ and potassium iodide in the acidic medium is______

20 mL of 0.5 M NaCl is required to coagulate 200 mL of As2S3 solution in 2 hours. The coagulating value of NaCl is____

For a reversible reaction A ⇌ B, the ΔH_{forward reaction} = 20 kJ mol^-1. The activation energy of the uncatalysed forward reaction is 300 kJ mol^-1. When the reaction is catalysed keeping the reactant concentration same, the rate of the catalysed forward reaction at 27°C is found to be same as that of the uncatalysed reaction at 327°C. The activation energy of the cataysed backward reactoion is ____ kJ mol^-1.

30.4 kJ is required to melt one mole of sodium chloride. The entropy change during melting is 28.4 JK-1 mol-1 . atm The melting point of sodium chloride Calculate is ___ K(Nearest Integer).

The volume (in mL) of 0.1 M AgNO₃ required for complete precipitation of chloride ions present in 20 mL of 0.01 M solution of [Cr(H₂O)₅CI]Cl₂ as silver chloride is___

In an oligopeptide named Alanylglycylphenyl alanyl isoleucine, the number of sp² hybridised carbons is_____.