List of top Chemistry Questions asked in JEE Advanced

The correct order of the wavelength maxima of the absorption band in the ultraviolet-visible region for the given complexes is:
Consider the depicted hydrogen (H) in the hydrocarbons given below. The most acidic hydrogen (H) is:

Considering ideal gas behavior, the expansion work done (in kJ) when 144 g of water is electrolyzed completely under constant pressure at 300 K is ____. Use: Universal gas constant $ R = 8.3 \, \text{J K}^{-1} \text{mol}^{-1} $; Atomic mass (in amu): H = 1, O = 16

The monomer (X) involved in the synthesis of Nylon 6,6 gives positive carbylamine test. If 10 moles of X are analyzed using Dumas method, the amount (in grams) of nitrogen gas evolved is ____. Use: Atomic mass of N (in amu) = 14

The correct match of the group reagents in List-I for precipitating the metal ion given in List-II from solutions is:

List-IList-II
(P) Passing H2S in the presence of NH4OH(1) Cu2+
(Q) (NH4)2CO3 in the presence of NH4OH(2) Al3+
(R) NH4OH in the presence of NH4Cl(3) Mn2+
(S) Passing H2S in the presence of dilute HCl(4) Ba2+
(5) Mg2+

Match the compounds in List-I with the appropriate observations in List-II and choose the correct option.

In an electrochemical cell, dichromate ions in aqueous acidic medium are reduced to $ \text{Cr}^{3+} $. The current (in amperes) that flows through the cell for 48.25 minutes to produce 1 mole of $ \text{Cr}^{3+} $ is ____. {Use: 1 Faraday $ = 96500 \, \text{C mol}^{-1} $
Molar volume ($ V_m $) of a van der Waals gas can be calculated by expressing the van der Waals equation as a cubic equation with $ V_m $ as the variable. The ratio (in mol dm$^{-3}$) of the coefficient of $ V_m^2 $ to the coefficient of $ V_m $ for a gas having van der Waals constants $ a = 6.0 \, \text{dm}^6 \, \text{atm mol}^{-2} $ and $ b = 0.060 \, \text{dm}^3 \, \text{mol}^{-1} $ at 300 K and 300 atm is ____. Use: Universal gas constant $ R = 0.082 \, \text{dm}^3 \, \text{atm mol}^{-1} \, \text{K}^{-1} $
What are the gases released when \(\mathrm{NH_4NO_2}\) and \(\mathrm{NH_4NO_3}\) are heated?
Calculate the sum of magnetic moments (in Bohr Magnetons, B.M.) of the complexes: \[ [\mathrm{MnCl}_6]^{3-} \quad \text{and} \quad [\mathrm{Mn(CN)}_6]^{3-} \]
Which of the following ions are diamagnetic?
The hydrolysis products of \(\mathrm{ICl}\), \(\mathrm{ClF_3}\), and \(\mathrm{BrF_5}\) are respectively:
Calculate the density of a solid (g/ml) with a CCP (Cubic close packed) structure. The edge length of unit cell is 400 pm. The molar mass of solid is 105.6 g/mol.
Among [Co(CN)4]4−, [Co(CO)3(NO)], XeF4, [PCl4 ]+, [PdCl4 ]2− , [ICl4 ]− , [Cu(CN)4]3− and P4 the total number of species with tetrahedral geometry is _____.
Consider the following reaction,
\(2H_2(g) + 2NO(g) \rightarrow N_2(g) + 2H_2O(g)\)
which follows the mechanism given below:
\(2NO(g)\underset{k_{-1}}{\stackrel{k_1}{\rightleftharpoons}} N_2O_2(g)\) (fast equilibrium)
\(N_2O_2(g)+H_2(g) \xrightarrow[]{K_2}N_2O(g)+H_2O\)  (slow reaction)
\(N_2O(g)+H_2(g) \xrightarrow[]{K_3}N_2(g)+H_2O\)  (fast reaction)
The order of the reaction is________
An organic compound P having molecular formula C6H6O3 gives ferric chloride test and does not have intramolecular hydrogen bond. The compound P reacts with 3 equivalents of NH2OH to produce oxime Q. Treatment of P with excess methyl iodide in the presence of KOH produces compound R as the major product. Reaction of R with excess iso-butylmagnesium bromide followed by treatment with H3O+ gives compound S as the major product.
The total number of methyl (−CH3) group(s) in compound S is ____.
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 of it remains undisintegrated.
When the age of the sample is P x108 years, the ratio of mass of Pb-206 to that of U-238 in the sample is found to be 7. The value of P is _____.
[Given: Half-life of U-238 is 4.5 x109 years; loge2 = 0.693]
For a double strand DNA, one strand is given below:
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 = 1.0 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.]
Vessel-1 contains w2 g of a non-volatile solute X dissolved in w1 g of water. Vessel-2 contains w2 g of another non-volatile solute Y dissolved in w1 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 of that of Y for their respective concentrations.
The elevation of boiling point for solution in Vessel-1 is _____ % of the solution in Vessel-2.
To form a complete monolayer of acetic acid on 1g of charcoal, 100 mL of 0.5M acetic acid was used. Some of the acetic acid remained unadsorbed. To neutralize the unadsorbed acetic acid, 40 mL of 1M NaOH solution was required. If each molecule of acetic acid occupies P x 10−23 m2 surface area on charcoal, the value of P is _____.
[Use given data: Surface area of charcoal = 1.5 x 102 m2g−1 ; Avogadro’s number (NA) = 6.0 x 1023 mol−1 ]
Among the following complexes, the total number of diamagnetic species is ______.
[Mn(NH3)6]3+, [MnCl6]3−, [FeF6]3−, [CoF6]3−, [Fe(NH3)6]3+, and [Co(en)3]3+
[Given, atomic number: Mn = 25, Fe = 26, Co = 27;
en = H2NCH2CH2NH2]
In the following reaction sequence, the major product P is formed.

Glycerol reacts completely with excess P in the presence of an acid catalyst to form Q. Reaction of Q with excess NaOH followed by the treatment with CaCl2 yields Ca-soap R, quantitatively. Starting with one mole of Q, the amount of R produced in gram is ______.
[Given, atomic weight: H = 1, C = 12, N = 14, O = 16, Na = 23, Cl = 35, Ca = 40]
Among V(CO)6, Cr(CO)5, Cu(CO)3, Mn(CO)5, Fe(CO)5, [Co(CO)3]3-, [Cr(CO)4]4-, and Ir(CO)3, the total number of species isoelectronic with Ni(CO)4 is _________.
[Given, atomic number: V = 23, Cr=24, Mn 25, Fe 26, Co 27, Ni 28, Cu = 29, Ir = 77]
Complete reaction of acetaldehyde with excess formaldehyde, upon heating with conc. NaOH solution, gives P and Q. Compound P does not give Tollens' test, whereas Q on acidification gives positive Tollens' test. Treatment of P with excess cyclohexanone in the presence of catalytic amount of p-toluenesulfonic acid (PTSA) gives product R.
Sum of the number of methylene groups (-CH2-) and oxygen atoms in R is _______
Consider the following volume−temperature (V−T) diagram for the expansion of 5 moles of an ideal monoatomic gas.
volume−temperature (V−T) diagram for the expansion of 5 moles of an ideal monoatomic gas.
Considering only P-V work is involved, the total change in enthalpy (in Joule) for the transformation of state in the sequence X→Y→Z is ______.
[Use the given data: Molar heat capacity of the gas for the given temperature range, CV,m = 12 J K−1mol−1 and gas constant, R=8.3 JK−1 mol−1]