NEET 2021 — Chemistry

The dihedral angle of the least stable conformer of ethane is:

Noble gases are so named because of their inertness towards reactivity. Identify an incorrect statement about them.

The major product of the following chemical reaction is:

$(\mathrm{C}{\mathrm{H}}_3{)}_2\mathrm{CH}-\mathrm{CH}=\mathrm{C}{\mathrm{H}}_2+\mathrm{HBr}\stackrel{({\mathrm{C}}_6{\mathrm{H}}_5\mathrm{CO}{)}_2{\mathrm{O}}_2}{\to }?$

A particular station of All India Radio, New Delhi, broadcasts on a frequency of 1,368 kHz (kilohertz). The wavelength of the electromagnetic radiation emitted by the transmitter is (speed of light $c=3.0\times 10^8\mathrm{m}{\mathrm{s}}^{-1}$):

The incorrect statement among the following is:

The right option for the number of tetrahedral and octahedral voids in a hexagonal primitive unit cell is:

Identify the compound that will react with Hinsberg's reagent to give a solid which dissolves in alkali.

Which of the following reactions is a metal displacement reaction? Choose the right option.

Given below are two statements:

Statement I: Aspirin and paracetamol belong to the class of narcotic analgesics.

Statement II: Morphine and heroin are non-narcotic analgesics.

In the light of the above statements, choose the correct answer from the options given below:

What is the IUPAC name of the organic compound formed in the following chemical reaction?

$\mathrm{Acetone}\underset{(\mathrm{ii}){\mathrm{H}}_2\mathrm{O},{\mathrm{H}}^{+}}{\overset{(\mathrm{i}){\mathrm{C}}_2{\mathrm{H}}_5\mathrm{MgBr},\mathrm{dry}\mathrm{ether}}{\to }}\mathrm{Product}$

Statement I: Acid strength increases in the order HF ≪ HCl ≪ HBr ≪ HI.

Statement II: As the size of the elements F, Cl, Br, I increases down the group, the bond strength of HF, HCl, HBr and HI decreases and so the acid strength increases.

In the light of the above statements, choose the correct answer from the options given below:

Which one among the following is the correct option for the right relationship between $C_P$ and $C_V$ for one mole of an ideal gas?

Match List-I with List-II.

Choose the correct answer from the options given below:

The following solutions were prepared by dissolving 10 g of glucose (${\mathrm{C}}_6{\mathrm{H}}_{12}{\mathrm{O}}_6$) in 250 mL of water ($P_1$), 10 g of urea ($\mathrm{C}{\mathrm{H}}_4{\mathrm{N}}_2\mathrm{O}$) in 250 mL of water ($P_2$) and 10 g of sucrose (${\mathrm{C}}_{12}{\mathrm{H}}_{22}{\mathrm{O}}_{11}$) in 250 mL of water ($P_3$). The right option for the decreasing order of osmotic pressure of these solutions is:

Which one of the following methods can be used to obtain a highly pure metal which is liquid at room temperature?

Tritium, a radioactive isotope of hydrogen, emits which of the following particles?

The correct option for the number of body-centred unit cells in all 14 types of Bravais lattice unit cells is:

The major product formed in the dehydrohalogenation reaction of 2-bromopentane is pent-2-ene. This product formation is based on:

The maximum temperature that can be achieved in a blast furnace is:

The molar conductances of NaCl, HCl and $\mathrm{C}{\mathrm{H}}_3\mathrm{COONa}$ at infinite dilution are 126.45, 426.16 and $91.0\mathrm{S}\mathrm{c}{\mathrm{m}}^2\mathrm{mo}{\mathrm{l}}^{-1}$ respectively. The molar conductance of $\mathrm{C}{\mathrm{H}}_3\mathrm{COOH}$ at infinite dilution is:

The ethylenediaminetetraacetate (EDTA) ion is:

The structures of beryllium chloride in the solid state and vapour phase are:

The correct structure of 2,6-dimethyldec-4-ene is:

The right option for the statement 'Tyndall effect is exhibited by' is:

Which one of the following polymers is prepared by addition polymerisation?

RBC deficiency is a deficiency disease of:

The correct sequence of bond enthalpy of the C–X bond is:

An organic compound contains 78% (by weight) carbon and the remaining percentage of hydrogen. The right option for the empirical formula of this compound is (atomic weight of C is 12, H is 1):

Among the following alkaline earth metal halides, the one which is covalent and soluble in organic solvents is:

$\mathrm{B}{\mathrm{F}}_3$ is a planar and electron-deficient compound. The hybridisation and number of electrons around the central atom, respectively, are:

The $\mathrm{p}{K}_b$ of dimethylamine and $\mathrm{p}{K}_a$ of acetic acid are 3.27 and 4.77 respectively at $T$ (K). The correct option for the pH of dimethylammonium acetate solution is:

Choose the correct option for the graphical representation of Boyle's law, which shows a graph of pressure vs. volume of a gas at different temperatures:

For a reaction A → B, the enthalpy of reaction is $-4.2\mathrm{kJ}\mathrm{mo}{\mathrm{l}}^{-1}$ and the enthalpy of activation is $9.6\mathrm{kJ}\mathrm{mo}{\mathrm{l}}^{-1}$. The correct potential energy profile for the reaction is shown in option:

The compound which shows metamerism is:

Zr ($Z=40$) and Hf ($Z=72$) have similar atomic and ionic radii because of:

Match List-I with List-II.

Choose the correct answer from the options given below:

The reagent R in the given sequence of chemical reactions is:

From the following pairs of ions, which one is not an isoelectronic pair?

The slope of the Arrhenius plot ($\ln k$ vs $\frac{1}{T}$) of a first order reaction is $-5\times 10^3$ K. The value of $E_a$ of the reaction is (given $R=8.314\mathrm{J}{\mathrm{K}}^{-1}\mathrm{mo}{\mathrm{l}}^{-1}$):

For the irreversible expansion of an ideal gas under isothermal conditions, the correct option is:

In which one of the following arrangements is the given sequence not strictly according to the property indicated against it?

The intermediate compound X in the following chemical reaction is:

The correct option for the value of the vapour pressure of a solution at 45 °C with benzene to octane in a molar ratio 3 : 2 is (at 45 °C the vapour pressure of benzene is 280 mm Hg and that of octane is 420 mm Hg; assume ideal behaviour):

The molar conductivity of 0.007 M acetic acid is $20\mathrm{S}\mathrm{c}{\mathrm{m}}^2\mathrm{mo}{\mathrm{l}}^{-1}$. What is the dissociation constant of acetic acid? (Given ${\lambda }_{{\mathrm{H}}^{+}}^{\circ }=350\mathrm{S}\mathrm{c}{\mathrm{m}}^2\mathrm{mo}{\mathrm{l}}^{-1}$ and ${\lambda }_{\mathrm{C}{\mathrm{H}}_3\mathrm{CO}{\mathrm{O}}^{-}}^{\circ }=50\mathrm{S}\mathrm{c}{\mathrm{m}}^2\mathrm{mo}{\mathrm{l}}^{-1}$)

$\mathrm{C}{\mathrm{H}}_3\mathrm{C}{\mathrm{H}}_2\mathrm{CO}{\mathrm{O}}^{-}\mathrm{N}{\mathrm{a}}^{+}\underset{\text{heat}}{\overset{?}{\to }}\mathrm{C}{\mathrm{H}}_3\mathrm{C}{\mathrm{H}}_3+\mathrm{N}{\mathrm{a}}_2\mathrm{C}{\mathrm{O}}_3$

Consider the above reaction and identify the missing reagent/chemical.

Match List-I with List-II.

Choose the correct answer from the options given below:

The product formed in the following chemical reaction is:

Which of the following molecules is non-polar in nature?

Match List-I with List-II.

Choose the correct answer from the options given below:

Choose the correct option for the total pressure (in atm) in a mixture of 4 g ${\mathrm{O}}_2$ and 2 g ${\mathrm{H}}_2$ confined in a total volume of one litre at 0 °C (given $R=0.082\mathrm{L}\mathrm{atm}\mathrm{mo}{\mathrm{l}}^{-1}{\mathrm{K}}^{-1}$, $T=273$ K):