List of top Chemistry Questions asked in JEE Advanced

The option(s) in which at least three molecules follow Octet Rule is(are)

Based on VSEPR model, match the xenon compounds given in List-I with the corresponding geometries and the number of lone pairs on xenon given in List-II and choose the correct option.

List I		List II
(P)	XeF₂	(1)	Trigonal bipyramidal and two lone pair of electrons
(Q)	XeF₄	(2)	Tetrahedral and one lone pair of electrons
(R)	XeO₃	(3)	Octahedral and two lone pair of electrons
(S)	XeO₃F₂	(4)	Trigonal bipyramidal and no lone pair of electrons
		(5)	Trigonal bipyramidal and three lone pair of electrons

Among \([Co(CN)_4]^{4-}\), \([Co(CO)_3(NO)]\), \(XeF_4\), \([PCl_4]^+\), \([PdCl_4]^{2-}\), \([ICl_4]^-\), \([Cu(CN)_4]^{3-}\), and \(P_4\), the total number of species with tetrahedral geometry is:

For a double-strand DNA, one strand is given below: The amount of energy required to split the double-strand DNA into two single strands is . kcal mol........\(^{-1}\). [Given: Average energy per H-bond for A-T base pair = 1 kcal mol\(^{-1}\), G-C base pair = 1.5 kcal mol\(^{-1}\), and A-U base pair = 1.25 kcal mol\(^{-1}\). Ignore electrostatic repulsion between the phosphate groups]

A sample initially contains only U-238 isotope of uranium. With time, some of the U-238 radioactively decays into Pb-206 while the rest remains undisintegrated. When the age of the sample is \( P \times 10^8 \) years, the ratio of the mass of Pb-206 to that of U-238 in the sample is found to be 7. The value of \( P \) is: \[ \text{[Given: Half-life of U-238 = \(4.5 \times 10^9\) years; \(\log_e2 = 0.693\)]} \]

In the following reaction sequence, the major product \(Q\) is:

To form a complete monolayer of acetic acid on 1 g of charcoal, 100 mL of 0.5 M acetic acid was used. Some of the acetic acid remained unadsorbed. To neutralize the unadsorbed acetic acid, 40 mL of 1 M NaOH solution was required. If each molecule of acetic acid occupies \(P \times 10^{-23} \, m^2\) surface area on charcoal, the value of \(P\) is \_\_\_\_\_. \text{[Use given data: Surface area of charcoal} = 1.5 \times 10^{2} \text{ m}^{2}\text{g}^{-1}; \text{Avogadro's number (N}_{\text{A}}) = 6.0 \times 10^{23} \text{mol}^{-1}]

Vessel-1 contains \(w_2\) g of a non-volatile solute \(X\) dissolved in \(w_1\) g of water. Vessel-2 contains \(w_2\) g of another non-volatile solute \(Y\) dissolved in \(w_1\) g of water. Both the vessels are at the same temperature and pressure. The molar mass of \(X\) is 80\% of that of \(Y\). The van’t Hoff factor for \(X\) is 1.2 times that of \(Y\) for their respective concentrations. The elevation of boiling point for solution in Vessel-1 is \_\_\_\_\_ \% of the solution in Vessel-2.

The compound(s) having peroxide linkage is (are):

The option(s) with the correct sequence of reagents for the conversion of P to Q is (are):

The species formed on fluorination of phosphorus pentachloride in a polar organic solvent are:

According to Bohr's model, the highest kinetic energy is associated with the electron in the:

An aqueous solution of hydrazine (\(N_2H_4\)) is electrochemically oxidized by \(O_2\), thereby releasing chemical energy in the form of electrical energy. One of the products generated from the electrochemical reaction is \(N_2(g)\). Choose the correct statement(s) about the above process:

An organic compound P with molecular formula C₉H₁₈O₂ decolorizes bromine water and also shows positive iodoform test. P on ozonolysis followed by treatment with H₂O₂ gives Q and R. While compound Q shows positive iodoform test, compound R does not give positive iodoform test. Q and R on oxidation with pyridinium chlorochromate (PCC) followed by heating give S and T, respectively. Both S and T show positive iodoform test.
Complete copolymerization of 500 moles of Q and 500 moles of R gives one mole of a single acyclic copolymer U. [Given, atomic mass: H =1, C = 12, O =16]

When potassium iodide is added to an aqueous solution of potassium ferricyanide, a reversible reaction is observed in which a complex P is formed. In a strong acidic medium, the equilibrium shifts completely towards P. Addition of zinc chloride to P in a slightly acidic medium results in a sparingly soluble complex Q.

For He⁺, a transition takes place from the orbit of radius 105.8 pm to the orbit of radius 26.45 pm. The wavelength (in nm) of the emitted photon during the transition is ___.
[Use: Bohr radius, a = 52.9 pm, Rydberg constant, 𝑅H = 2.2 × 10⁻¹⁸ J, Planck’s constant, h = 6.6 × 10⁻³⁴ J s, Speed of light, c = 3 × 10⁸ m s⁻¹]

Among [I₃]⁺ , [SiO₄]^4-, SO₂Cl₂, XeF₂, SF₄, ClF₃, Ni(CO)_4, XeO₂F₂, [PtCl_4]²⁻, XeF₄, and SOCl₂, the total number of species having sp³ hybridised central atom is ______.

The correct molecular orbital diagram for F₂ molecule in the ground state is

On decreasing the 𝑝H from 7 to 2, the solubility of a sparingly soluble salt (MX) of a weak acid (HX) increased from 10⁻⁴ mol L⁻¹ to 10⁻³mol L⁻¹. The 𝑝Ka of HX is

H₂S (5 moles) reacts completely with acidified aqueous potassium permanganate solution. In this reaction, the number of moles of water produced is x, and the number of moles of electrons involved is y. The value of (x + y) is ____.

The stoichiometric reaction of 516 g of dimethyldichlorosilane with water results in a tetrameric cyclic product X in 75% yield. The weight (in g) of X obtained is___. [Use, molar mass (g mol⁻¹): H = 1, C = 12, O = 16, Si = 28, Cl = 35.5]