List of top Chemistry Questions asked in NEET (UG)

In which of the following molecules are all the bonds not equal?

[Cr(H₂O)₆]Cl₃ (at. no. of Cr = 24) has a magnetic moment of 3.83 BM, the correct distribution of 3d electrons in the chromium of the complex is:

The enthalpy and entropy change for the reaction : Br₂(l) + Cl₂(g) → 2BrCl(g) are 30 kJ mol^-1 and 105 JK^-1 mol^-1 respectively. The temperature at which the reaction will be in equilibrium is :

The enthalpy of combustion of H₂, cyclohexene (C₆H₁₀) and cyclohexene (C₆H₁₂) are -241, -3800 and -3920 kJ per mol respectively. Heat of hydrogenation of cyclohexene is:

Assume each reaction is carried out in an open container. For which reaction will ∆H = ∆E?

More number of oxidation states are exhibited by the actinides than by the lanthanides. The main reason for this is:

In which of the following pairs are both the ions coloured in aqueous solution? (Atomic number: Sc = 21, Ti = 22, Ni = 28, Cu = 29, Co = 27)

Identify the correct statement for change of Gibbs energy for a system ($\Delta G_{system}$) at constant temperature and pressure :

The enthalpy and entropy change for the reaction : $ {Br2(\ell) + Cl2(g) -> 2BrCl(g)}$ are $30 \,kJmol^{-1}$ and $105\,JK^{-1} mol^{-1}$ respectively. The temperature at which the reaction will be in equilibrium is :

Which one of the following arrangements represents the correct order of electron gain enthalpy (with negative sign) of the given atomic species?

$4.5\, g$ of aluminium (at. mass $27$ amu) is deposited at cathode from a molten electrolyte containing $Al^{3+}$ ions by a certain quantity of electric charge.The volume of hydrogen produced at STP from $H^+$ ions in a solution by the same quantity of electric charge will be

A solution of urea (mol mass $56\, g\, mol^{-1})$ boils at $100.18 ^\circ\,C$ at the atmospheric pressure. If $K_f$ and $K_b$ for water are $1.86$ and $0.512\, K\, kg$ $mol^{-1}$ the above solution will freeze at

Which functional group participates in disulphide bond formation in proteins?

The cell membranes are mainly composed of

Which one of the following is expected to exhibit optical isomerism? (en = ethylenediamine)

H₂S gas when passed through a solution of cations containing HCl precipitates the cations of second group of qualitative analysis but not those belonging to the fourth group. It is because:

At $ 25^\circ $, the dissociation constant of a base, BOH is $ 1.0 \times 10^{-12} $. The concentration of hydroxyl ions in 0.01 M aqueous solution of the base would be

For a first order reaction, $A \longrightarrow B$, the reaction rate at reactant concentration of $0.01\, M$ is found to be $2.0 \times 10^{-5} \, mol \, \, L^{-1} s^{-1}$. The half-life period of the reaction is

$ H_2S $ gas when passed through a solution of cations containing $HCl$ precipitates the cations of second group in qualitative analysis but not those belonging to the fourth group. It is because

Which one of the following is an inner orbital complex as well as diamagnetic in behaviour? (At. no. of Zn = 30, Cr = 24, Co = 27, Ni = 28)

The best method for the separation of naphthalene and benzoic acid from their mixture is

Nucleotides are building blocks of nucleic acids. Each nucleotide is a composite molecule formed by

The mass of carbon anode consumed (giving only carbon dioxide) in the production of 270kg of aluminum metal from bauxite by the Hall process is: (Atomic mass Al = 27)

The correct order in which the O—O bond length increases in the following is: