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

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

Values of work function (Wo) for a few metals are given below

Metal	Li	Na	K	Mg	Cu	Ag
Wo/eV	2.42	2.3	2.25	3.7	4.8	4.3

The number of metals which will show photoelectric effect when light of wavelength 400nm falls on it is____ 

Given: h = 6.6 × 10^-34 J s 
c = 3 x 10⁸ m s^-1 
e = 1.6 x 10^-19 C

At 600K, the root mean square (rms) speed of gas X (molar mass = 40) is equal to the most probable speed of gas Y at 90K. The molar mass of the gas Y is ____ g mol^-1. (Nearest integer)

For lead storage battery pick the the correct statements.
A. During charging of battery, PbSO4 on anode is converted into PbO2 
B. During charging of battery, PbSO4 on cathode is converted into PbO2 
C. Lead storage battery, consists of grid of lead packed with PbO2 as anode 
D. Lead storage battery has ~ 38% solution of sulphuric acid as an electrolyte 
Choose the correct answer from the options given below:

Given below are two statements: one is labelled as Assertion A and the other is labelled as Reason R.
Assertion A: In the Ellingham diagram, a sharp change in slope of the line is observed for Mg → MgO at ~ 1120°C 
Reason R: There is a large change of entropy associated with the change of state. 
In the light of the above statements, choose the correct answer from the options given below : 

Given below are two statement: one is labelled as Assertion A and the other is labelled as Reason R.
Assertion A: 5f electrons can participate in bonding to a far greater extent than 4f electrons 
Reason R: 5f orbitals are not as buried as 4f orbitals 
In the light of the above statements, choose the correct answer from the options given below: 

A metal chloride contains 55.0% of chlorine by weight. 100 mL vapours of the metal chloride at STP weigh 0.57 g. The molecular formula of the metal chloride is (Given: Atomic mass of chlorine is 35.5u)

Among the following compounds, the one which shows highest dipole moment is

Given below are two statements:
Statement I: Permutit process is more efficient compared to the synthetic resin method for the softening of water.
Statement II: Synthetic resin method results in the formation of soluble sodium salts.
In the light of the above statements, choose the most appropriate answer from the options given below:

The number of sp² hybridized carbon atoms in the following peptide is Ala – Phe – Gly – Ala – Phe - Ley

For the 1st order reactions, the ratio of t_50% to t_87.5% will be:

Based on the given figure, the number of correct statement/s is/are ______.

A. Surface tension is the outcome of equal attractive and repulsion forces acting on the liquid molecule in bulk.
B. Surface tension is due to uneven forces acting on the molecules present on the surface.
C. The molecule in the bulk can never come to the liquid surface.
D. The molecules on the surface are responsible for vapour pressure if the system is a closed system.

Determine the amount of urea (NH₂CONH₂) to be added in 1000 g of water to decrease its vapour presssure by 25%. 
Given: Molar mass of N. C. O and H are 14. 12. 16 and 1 2 mol^-1 respectively.

Correct order of first ionization energy of Li, Be, C, B, N, O, F

How many moles of \(Ba_3(PO_4)_2\) will be formed by the reaction of \(5\) moles of \(BaCl_2\) and \(3\) moles of \(Na_3(PO_4)\).

How many bromo products are formed when ethane is reacted with excess of \(Br_2\) on heating?

Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R).
A ⇒ Spin only magnetic moment of [Fe(CN)₆]^–3 is 1.73 B.M. and [Fe(H₂O)₆]⁺³ is 5.92 B.M.
R ⇒ In both cases Fe have +3 oxidation state
In the light of the above statements, write the detailed answer:

Given below are two statement: one is labelled as Assertion (A) and the other is labelled as Reason (R). 
\(A ⇒\) Spin only magnetic moment of \([Fe(CN)_6]^{–3}\) is \(1.73\) B.M. and \([Fe(H_2O)_6]^{+3}\) is \(5.92\) B.M. 
\(R ⇒\) In both cases Fe have \(+3\) oxidation state. 
In the light of the above statements, write the detailed answer:

For a metal ion magnetic moment is calculated to be 4.9BM. Find the number of unpaired.

For a first-order reaction, if the value of \(t_{\frac{1}{2}}\) is T, then the value of \(t_{\frac{7}{8}}\) will be_____ T.

Find out difference in oxidation state of Xe in completely Hydrolysed form of XeF₄ and XeF₆