List of top Chemistry Questions asked in JEE Advanced

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]
A closed vessel contains 10 g of an ideal gas X at 300 K, which exerts 2 atm pressure. At the same temperature, 80 g of another ideal gas Y is added to it and the pressure becomes 6 atm. The ratio of root mean square velocities of X and Y at 300 K is
According to Bohr’s model, the highest kinetic energy is associated with the electron in the
The option(s) with correct sequence of reagents for the conversion of P to Q is(are)
The option(s) with correct sequence of reagents for the conversion of P to Q is
In the following reaction sequence, the major product Q is
\(\text{L-Glucose}\xrightarrow[ii)Cr_2,775K,10-20 \text{atm}]{i)HI, \Delta}P\xrightarrow[UV]{Cl_2(excess)}Q\)
Among the following, the correct statement(s) for electrons in an atom is(are)
Among the following options, select the option in which each complex in Set-I shows geometrical isomerism and the two complexes in Set-II are ionization isomers of each other.
[en = H2NCH2CH2NH2]
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]
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.
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 [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 _____.
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 ____.
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.
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.]
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]
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 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________
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]
The species formed on fluorination of phosphorus pentachloride in a polar organic solvent are
An aqueous solution of hydrazine (N2H4) is electrochemically oxidized by O2, thereby releasing chemical energy in the form of electrical energy. One of the products generated from the electrochemical reaction is N2(g).
Choose the correct statement(s) about the above process
The compound(s) having peroxide linkage is(are)
In a metal deficient oxide sample, MXY2O4(M and Y are metals), M is present in both +2 and +3 oxidation states and Y is in +3 oxidation state. If the fraction of M2+ ions present in M is \(\frac{1}{3}\), the value of X is______.
The option(s) in which at least three molecules follow Octet Rule is(are)