List of top Chemistry Questions asked in JEE Advanced

The maximum number of possible isomers (including stereoisomers) which may be formed on mono-bromination of 1-methylcyclohex-1-ene using Br2 and UV light is ___.

In the reaction given below, the total number of atoms having sp2 hybridization in the major product P is ___.
hybridization
The total number of possible isomers for \([ \text{Pt(NH}_3\text{)}_4\text{Cl}_2 ]\text{Br}_2\) is ___.

At 298 K, the limiting molar conductivity of a weak monobasic acid is 4 × 102 S cm2 mol–1. At 298 K, for an aqueous solution of the acid, the degree of dissociation is a and the molar conductivity is y × 102 S cm2 mol–1. At 298 K, upon 20 times dilution with water, the molar conductivity of the solution becomes 3y × 102 S cm2 mol–1.

The reaction of x g of Sn with HCl quantitatively produced a salt. The entire amount of the salt reacted with y g of nitrobenzene in the presence of the required amount of HCl to produce 1.29 g of an organic salt (quantitatively).
(Use Molar masses (in g mol–1) of H, C, N, O, Cl and Sn as 1, 12, 14, 16, 35 and 119, respectively).

A sample (5.6 g) containing iron is completely dissolved in cold dilute HCl to prepare a 250 mL of solution. Titration of 25.0 mL of this solution requires 12.5 mL of 0.03 M KMnO4 solution to reach the endpoint. Number of moles of Fe2+ present in 250 mL solution is x × 10–2 (consider complete dissolution of FeCl2). The amount of iron present in the sample is y% by weight.
(Assume: KMnO4 reacts only with Fe2+ in the solution Use: Molar mass of iron as 56 g mol–1)

The amount of energy required to break a bond is the same as the amount of energy released when the same bond is formed. In a gaseous state, the energy required for homolytic cleavage of a bond is called Bond Dissociation Energy (BDE) or Bond Strength. BDE is affected by the s-character of the bond and the stability of the radicals formed. Shorter bonds are typically stronger bonds. BDEs for some bonds are given below:
homolytic cleavage

The reaction of K3[Fe(CN)6] with freshly prepared FeSO4 solution produces a dark blue precipitate called Turnbull’s blue. The reaction of K4[Fe(CN)6] with the FeSO4 solution in the complete absence of air produces a white precipitate X, which turns blue in the air. Mixing the FeSO4 solution with NaNO3, followed by slow addition of concentrated H2SO4 through the side of the test tube produces a brown ring.

One mole of an ideal gas at 900 K, undergoes two reversible processes, I followed by II, as shown below. If the work done by the gas in the two processes are the same, the value of \(\ln \frac{v_3}{v_2}\) is _____
two reversible processes
(U: internal energy, S: entropy, p: pressure, V: volume, R: gas constant)
(Given: molar heat capacity at constant volume, \(C_v,m\) of the gas is \(\frac{5}{2}\)R)

Consider a helium (He) atom that absorbs a photon of wavelength 330 nm. The change in the velocity (in cm s-1) of the He atom after the photon absorption is_____.
(Assume: Momentum is conserved when the photon is absorbed.
Use: Planck constant = 6.6 × 10-34 J s, Avogadro number = 6 × 1023 mol-1, Molar mass of He = 4 g mol-1)

Correct option(s) for the following sequence of reactions is(are)
Sequence of Reaction
An ideal gas undergoes a reversible isothermal expansion from the state I to state II followed by a reversible adiabatic expansion from state II to state III. The correct plot(s) representing the changes from the state I to state III is(are) 
(p: pressure, V: volume, T: temperature, H: enthalpy, S: entropy)
Given:
Glucose
The compound(s), which on reaction with HNO3 will give the product having a degree of rotation, [α]D = –52.7º is(are);
The correct statement(s) related to the metal extraction processes is(are)
The reaction sequence(s) that would lead to o-xylene as the major product is(are).
The correct statement(s) related to oxoacids of phosphorous is(are)
The boiling point of water in a $0.1$ molal silver nitrate solution (solution $A$ ) is $x ^{\circ} C$. To this solution $A$, an equal volume of $0.1$ molal aqueous barium chloride solution is added to make a new solution $B$. The difference in the boiling points of water in the two solutions $A$ and $B$ is $y \times 10^{-2}{ }^{\circ} C$
(Assume: Densities of the solutions $A$ and $B$ are the same as that of water and the soluble salts dissociate completely
Use: Molal elevation constant (Ebullioscopic Constant), $K _{ b }=0.5 \,K \,kg\, mol ^{-1}$; Boiling point of pure water as $100^{\circ} C$)
For the reaction, $X (s) \rightleftharpoons Y (s)+ Z (g)$, the plot of $\ln \frac{p_{ Z }}{p^{0}}$ versus $\frac{10^{4}}{T}$ is given below (in solid line), where $p_{ z }$ is the pressure (in bar) of the gas $Z$ at temperature $T$ and $p^0=1$ bar
For the reaction, 𝐗(𝑠) ⇌ 𝐘(𝑠) + 𝐙(𝑔), the plot of ln 𝑝𝐙 𝑝o versus 104 𝑇 is given below (in solid line), where 𝑝𝐙 is the pressure (in bar) of the gas Z at temperature T and 𝑝 o = 1 bar.
 (Given, $\frac{ d (\ln K)}{ d \left(\frac{1}{T}\right)}=-\frac{\Delta H^{0}}{R}$, where the equilibrium constant, $K=\frac{p_{z}}{p^{0}}$ and the gas constant, $R=8314 \,J \,K ^{-1} mol ^{-1}$ )
For the following reaction scheme, percentage yields are given along the arrow: 
Xg and yg are mass of R and U, respectively
$X\, g$ and $y \,g$ are mass of $R$ and $U$, respectively. (Use : Molar mass (in $g \,mol^{-1})$ of $H, C$ and $O$ as $1, 12$ and $16$, respectively)
With respect to the compounds I-V, choose the correct statement(s).
With respect to the compounds I-V
An acidified solution of $0.05 \,M\, Zn ^{2+}$ is saturated with $0.1 \,M \,H _{2} S$. What is the minimum molar concentration $(M)$ of $H ^{+}$required to prevent the precipitation of $ZnS$ ?
Use $K_{s p}( ZnS )=1.25 \times 10^{-22}$ and overall dissociation constant of $H _{2} S. K _{ NET }=K_{1} K_{2}=1 \times 10^{-21}$
Which of the following liberates $O _{2}$ upon hydrolysis?
Choose the correct statement(s) among the following:
Newman projections P, Q, R and S are shown below:
Newman projections
 Which one of the following options represents identical molecules?
If the distribution of molecular speeds of a gas is as per the figure shown below, then the ratio of the most probable, the average, and the root mean square speeds, respectively, is
distribution of molecular speeds of a gas