datavorous/entrance-exam-dataset huggingface dataset:
Why does a deviation in atomic radius occur between gallium and aluminum?

Options:
A Due to a decrease in the number of electrons.
B Due to a decrease in nuclear charge.
C Due to poor screening effect from additional d-electrons.
D Due to the presence of additional 10 f-electrons.

The correct answer is:
Due to poor screening effect from additional d-electrons.

Solution:
The deviation in atomic radius between gallium and aluminum occurs because the presence of additional 10 d-electrons offers only poor screening effect for the outer electrons from the increased nuclear charge in gallium.

Topic: Chemistry, p Block Elements (Group 13 & 14), NEET
Why does a metal bar feel hotter than a wooden bar at the same temperature and cooler than the wooden bar if both are colder than room temperature?

Options:
A Metals have a higher capacity to conduct heat compared to wood.
B Metals have a higher specific heat capacity than wood.
C Metals have a higher melting point than wood.
D Metals have a lower specific heat capacity than wood.

The correct answer is:
Metals have a higher capacity to conduct heat compared to wood.

Solution:
Correct Option is : (A)
Metals have a higher capacity to conduct heat compared to wood.

Topic: Chemistry, Thermal Properties of Matter, NEET
Why does a molecule on the surface of a liquid experience a net attractive force towards the interior of the liquid?

Options:
A Lack of adhesion
B Capillary action
C Surface tension
D High density

The correct answer is:
Surface tension

Solution:
A molecule on the surface of a liquid experiences a net attractive force towards the interior of the liquid due to surface tension.

Topic: Chemistry, States of Matter, NEET
Why does a person driving a car, without wearing a seat belt, fall forward and hit their head against the steering wheel when suddenly applying the brakes on seeing a child on the road ahead?

Options:
A Insufficient friction between the seat and the person's body
B Inadequate speed of the vehicle
C Lack of attention on the road
D Poor visibility due to bad weather

The correct answer is:
Insufficient friction between the seat and the person's body

Solution:
Correct Option is : (A)
Insufficient friction between the seat and the person's body

Topic: Chemistry, Laws of Motion, NEET
Why does a solid sphere have a smaller moment of inertia than a hollow cylinder of the same mass and radius, about an axis passing through their axes of symmetry?

Options:
A The mass distribution of the solid sphere is more concentrated towards its center compared to the hollow cylinder.
B The solid sphere has a smaller radius than the hollow cylinder, resulting in a smaller moment of inertia.
C The material used to make the solid sphere is less dense compared to the material used for the hollow cylinder, affecting the moment of inertia.
D The solid sphere has a larger mass than the hollow cylinder, contributing to a smaller moment of inertia.

The correct answer is:
The mass distribution of the solid sphere is more concentrated towards its center compared to the hollow cylinder.

Solution:
Correct Option is : (A)
The mass distribution of the solid sphere is more concentrated towards its center compared to the hollow cylinder.

Topic: Chemistry, Rotational Motion, NEET
Why does a spinning cricket ball in the air not follow a parabolic trajectory?

Options:
A Because the Magnus effect causes it to deviate from a parabolic path.
B Due to the Coriolis effect altering its trajectory.
C Because of gravitational forces acting differently on spinning objects.
D None of the above.

The correct answer is:
Because the Magnus effect causes it to deviate from a parabolic path.

Solution:
Correct Option is : (A)
Because the Magnus effect causes it to deviate from a parabolic path.

Topic: Chemistry, Mechanical Properties of Fluids, NEET
Why does acetylation of the -NH2group of aniline reduce its activating effect?

Options:
A Acetylation increases the electron density on the nitrogen atom, leading to decreased activation.
B Acetylation enhances the resonance stabilization of the amino group, weakening its activating effect.
C Because the lone pair on the nitrogen atom is in conjugation with the carbonyl group in acetylated aniline. As a result, the lone pair of electrons on nitrogen is less available for donation to benzene ring by resonance
D Acetylation decreases the steric hindrance around the amino group, making it less reactive.

The correct answer is:
Because the lone pair on the nitrogen atom is in conjugation with the carbonyl group in acetylated aniline. As a result, the lone pair of electrons on nitrogen is less available for donation to benzene ring by resonance

Solution:
Correct Option is : (C)
Because the lone pair on the nitrogen atom is in conjugation with the carbonyl group in acetylated aniline. As a result, the lone pair of electrons on nitrogen is less available for donation to benzene ring by resonance

Topic: Chemistry, Amines, NEET
Why does an ice cube float on water?

Options:
A Because the density of ice is higher than that of water
B Because the density of ice is equal to that of water
C Because the density of ice is less than that of water
D Because the density of ice is unrelated to water

The correct answer is:
Because the density of ice is less than that of water

Solution:
An ice cube floats on water because the density of ice is less than that of water, allowing it to stay on the water's surface.

Topic: Chemistry, Hydrogen, NEET
Why does an optical pyrometer (for measuring high temperatures) calibrated for an ideal black body radiation give too low a value for the temperature of a red-hot iron piece in the open, but gives a correct value for the temperature when the same piece is in the furnace?

Options:
A The pyrometer is not sensitive to red-hot temperatures.
B The black body radiation in the open interferes with the pyrometer's accuracy.
C An increase in the temperature of open space reduces the radiation energy. When the same piece of iron is placed in a furnace, the radiation energy, E=σT4
D The furnace provides a controlled environment for accurate temperature measurement.

The correct answer is:
An increase in the temperature of open space reduces the radiation energy. When the same piece of iron is placed in a furnace, the radiation energy, E=σT4

Solution:
Correct Option is : (C)
An increase in the temperature of open space reduces the radiation energy. When the same piece of iron is placed in a furnace, the radiation energy, E=σT4

Topic: Chemistry, Thermal Properties of Matter, NEET
Why does aniline have a higher pKb value compared to ammonia?

Options:
A Aniline has a stronger inductive effect.
B Aniline has a resonance-stabilised structure.
C Aniline has a larger molar mass.
D Aniline has a higher electronegativity.

The correct answer is:
Aniline has a resonance-stabilised structure.

Solution:
Aniline has a resonance-stabilized structure with multiple resonating forms, making it more stable and less basic compared to ammonia.

Topic: Chemistry, Amines, NEET
Why does anisole undergo bromination with bromine in ethanoic acid even in the absence of iron (III) bromide catalyst?

Options:
A Anisole is a strong Lewis acid
B Anisole is a strong Lewis base
C Anisole activates the benzene ring
D Anisole deactivates the benzene ring

The correct answer is:
Anisole activates the benzene ring

Solution:
Anisole activates the benzene ring due to the methoxy group, making it more reactive towards electrophilic aromatic substitution reactions like bromination.

Topic: Chemistry, Alcohols Phenols and Ethers, NEET
Why does aqueous copper sulphate solution (blue in colour) exhibit the following experimental results that is,It forms a green precipitate with aqueous potassium fluoride and a bright green solution with aqueous potassium chloride?

Options:
A Copper sulphate undergoes a redox reaction with fluoride ions, leading to the green precipitate and bright green solution.
B It reacts with KF to form green-coloured [CuF4]2−and reacts with KCL to form bright green-coloured [CuCl4​]2−In both these cases, the weak field ligand water is replaced by the F−and Cl−ions.
C The green colour is due to the interaction of copper sulphate with fluoride and chloride ions.
D Copper sulphate reacts differently with fluoride and chloride ions due to differences in ligand strength.

The correct answer is:
It reacts with KF to form green-coloured [CuF4]2−and reacts with KCL to form bright green-coloured [CuCl4​]2−In both these cases, the weak field ligand water is replaced by the F−and Cl−ions.

Solution:
Correct Option is : (B)
It reacts with KF to form green-coloured [CuF4]2−and reacts with KCL to form bright green-coloured [CuCl4​]2−In both these cases, the weak field ligand water is replaced by the F−and Cl−ions.

Topic: Chemistry, Coordination Compounds, NEET
Why does benzene undergo electrophilic substitution reactions easily and nucleophilic substitutions with difficulty?

Options:
A Benzene undergoes electrophilic substitution reactions easily because it has a high electron density due to its resonance-stabilized structure, making it attractive to electrophiles. Nucleophilic substitutions are difficult because benzene's electron-rich nature repels nucleophiles.
B Benzene undergoes electrophilic substitution reactions easily because it has a low electron density due to its resonance-stabilized structure, making it attractive to electrophiles. Nucleophilic substitutions are difficult because benzene's electron-poor nature repels nucleophiles.
C Benzene undergoes electrophilic substitution reactions easily because it has a low electron density due to its resonance-stabilized structure, making it attractive to electrophiles. Nucleophilic substitutions are difficult because benzene's electron-rich nature repels nucleophiles.
D Benzene does not undergo electrophilic or nucleophilic substitutions because it is a highly stable compound and is unreactive towards both electrophiles and nucleophiles.

The correct answer is:
Benzene undergoes electrophilic substitution reactions easily because it has a high electron density due to its resonance-stabilized structure, making it attractive to electrophiles. Nucleophilic substitutions are difficult because benzene's electron-rich nature repels nucleophiles.

Solution:
Correct Option is : (A)
Benzene undergoes electrophilic substitution reactions easily because it has a high electron density due to its resonance-stabilized structure, making it attractive to electrophiles. Nucleophilic substitutions are difficult because benzene's electron-rich nature repels nucleophiles.

Topic: Chemistry, Hydrocarbons, NEET
Why does beryllium (Be2+) have a higher electron affinity compared to other alkaline earth metals?

Options:
A Larger atomic radius of Be.
B Smaller ionic radius of Be2+ ion.
C Lower ionization energy of Be.
D Higher electronegativity of Be.

The correct answer is:
Smaller ionic radius of Be2+ ion.

Solution:
The smaller ionic radius of Be2+ ion contributes to its higher electron affinity.

Topic: Chemistry, s Block Elements, NEET
Why does bleeding stop by rubbing moist alum?

Options:
A Alum acts as a coagulant and seals the wound.
B Alum induces vasoconstriction, reducing blood flow.
C Alum promotes blood clotting.
D Alum acts as an antiseptic.

The correct answer is:
Alum acts as a coagulant and seals the wound.

Solution:
Correct Option is : (A)
Alum acts as a coagulant and seals the wound.

Topic: Chemistry, Surface Chemistry, NEET
Why does boron have an unusually high melting point?

Options:
A Due to its metallic properties
B Due to its crystalline lattice
C Due to its low density
D Due to its high electrical conductivity

The correct answer is:
Due to its crystalline lattice

Solution:
Boron has an unusually high melting point "due to a very strong crystalline lattice."

Topic: Chemistry, p Block Elements (Group 13 & 14), NEET
Why does boron primarily form covalent compounds?

Options:
A Because it has a high number of electrons
B Because of its small size and high ionization enthalpy
C Because it has a low melting point
D Because it has a high electrical conductivity

The correct answer is:
Because of its small size and high ionization enthalpy

Solution:
Due to the small size of boron, the sum of its first three ionization enthalpies is very high. This prevents it from forming +3 ions and forces it to form only covalent compounds.

Topic: Chemistry, p Block Elements (Group 13 & 14), NEET
Why does boron trifluoride (BF₃) behave as a Lewis acid?

Options:
A Because it has a complete octet in its valence shell.
B Because it readily donates electron pairs to other molecules.
C Because it has an incomplete octet and can accept an electron pair from a Lewis base.
D Because it forms ionic bonds with Lewis bases.

The correct answer is:
Because it has an incomplete octet and can accept an electron pair from a Lewis base.

Solution:
Correct Option is : (C)
Because it has an incomplete octet and can accept an electron pair from a Lewis base.

Topic: Chemistry, p Block Elements (Group 15, 16, 17 & 18), NEET
Why does boron (Z = 5) have a smaller first ionization enthalpy than beryllium (Z = 4)?

Options:
A Boron has fewer electrons.
B Boron has a smaller nucleus.
C Boron has a greater nuclear charge.
D Boron has more shielding electrons.

The correct answer is:
Boron has more shielding electrons.

Solution:
Boron has a smaller first ionization enthalpy than beryllium because the 2p-electron of boron is more shielded from the nucleus by the inner core of electrons than the 2s electrons of beryllium.

Topic: Chemistry, Classification of Elements and Periodicity in Properties, NEET
Why does cis-polyisoprene possess elastic property?

Options:
A Due to less branching
B Due to strong intermolecular forces
C The cis-polyisoprene molecule consists of various chains held together by weak van der waals interactions and has a coiled structure. Thus, it can be stretched like a spring and exhibits elastic properties.
D Due to its crystalline structure

The correct answer is:
The cis-polyisoprene molecule consists of various chains held together by weak van der waals interactions and has a coiled structure. Thus, it can be stretched like a spring and exhibits elastic properties.

Solution:
Correct Option is : (C)
The cis-polyisoprene molecule consists of various chains held together by weak van der waals interactions and has a coiled structure. Thus, it can be stretched like a spring and exhibits elastic properties.

Topic: Chemistry, Polymers, NEET
Why does compound (A) given below not form an oxime?

Options:
A Glucose pentaacetate [structure A] doesn’t have a free —OH group at C1and so can’t be converted to the open chain form to give —CHO group and hence doesn’t form the oxime.
B Glucose pentaacetate is a cyclic compound, and oxime formation occurs primarily in linear molecules.
C Glucose pentaacetate is too large to participate in oxime reactions.
D Glucose pentaacetate is highly stable and does not readily undergo chemical reactions.

The correct answer is:
Glucose pentaacetate [structure A] doesn’t have a free —OH group at C1and so can’t be converted to the open chain form to give —CHO group and hence doesn’t form the oxime.

Solution:
Correct Option is : (A)
Glucose pentaacetate [structure A] doesn’t have a free —OH group at C1and so can’t be converted to the open chain form to give —CHO group and hence doesn’t form the oxime.

Topic: Chemistry, Biomolecules, NEET
Why does copper not replace hydrogen from acids?

Options:
A Copper has a lower reactivity than hydrogen.
B Copper is a poor conductor of electricity.
C Copper does not have the necessary valency to replace hydrogen.
D Copper has a higher reduction potential than hydrogen.

The correct answer is:
Copper has a higher reduction potential than hydrogen.

Solution:
Correct Option is : (D)
Copper has a higher reduction potential than hydrogen.

Topic: Chemistry, d and f Block Elements, NEET
Why does Cr have the electronic configuration 3d54s1 instead of 3d44s2?

Options:
A Because 3d orbitals are completely filled
B Because of the energy gap between 3d and 4s orbitals
C Because 4s orbitals are completely filled
D Because of the little energy difference between (n-1)d and ns orbitals

The correct answer is:
Because of the energy gap between 3d and 4s orbitals

Solution:
The energy gap between the 3d and 4s orbitals is small enough to prevent electrons from entering the 3d orbitals.

Topic: Chemistry, d and f Block Elements, NEET
Why does diamond's three-dimensional network of C-C bonds have a high melting point?

Options:
A Due to the presence of weak Van der Waals forces
B Due to the presence of metallic bonds
C Due to the presence of strong covalent bonds
D Due to the absence of any bonding between carbon atoms

The correct answer is:
Due to the presence of strong covalent bonds

Solution:
The high melting point of diamond results from the presence of strong C-C covalent bonds in its three-dimensional network.

Topic: Chemistry, p Block Elements (Group 13 & 14), NEET
Why does DNA move towards the positive electrode in Agarose gel electrophoresis?

Options:
A DNA is positively charged
B Agarose gel is positively charged
C DNA is negatively charged
D Agarose gel is negatively charged

The correct answer is:
DNA is negatively charged

Solution:
DNA is a negatively charged molecule, so it moves towards the positive electrode (anode) during Agarose gel electrophoresis.

Topic: Biology, Biotechnology - Principles and Processes, NEET
Why does even a moderate amount of organic matter decomposing in water deplete the dissolved oxygen?

Options:
A Organic matter releases oxygen.
B Bacteria consume organic matter.
C Bacteria produce organic matter.
D Organic matter is not related to dissolved oxygen levels.

The correct answer is:
Bacteria consume organic matter.

Solution:
Bacteria decompose organic matter in water, and in doing so, they consume dissolved oxygen, leading to a reduction in oxygen levels.

Topic: Chemistry, Environmental Chemistry, NEET
Why does F2 have a smaller enthalpy of dissociation compared to Cl2?

Options:
A Smaller atomic size of fluorine
B Greater electron-electron repulsion in F2
C Higher ionization enthalpy of fluorine
D Weaker fluorine-fluorine bond

The correct answer is:
Greater electron-electron repulsion in F2

Solution:
F2 has a smaller enthalpy of dissociation compared to Cl2 due to the relatively large electron-electron repulsion among the lone pairs in the F2 molecule, where they are much closer to each other than in the case of Cl2.**

Topic: Chemistry, p Block Elements (Group 15, 16, 17 & 18), NEET
Why does Fe have a comparatively low Eo value?

Options:
A The removal of an electron from the stable d10 configuration of Fe2+
B The stability of Fe3+ with a noble gas configuration
C The half-filled t2g level of Fe2+
D The removal of an electron from the d5 configuration of Fe2+

The correct answer is:
The stability of Fe3+ with a noble gas configuration

Solution:
The paragraph mentions that the comparatively low Eo value for Fe shows the extra stability of Fe3+ (d5).

Topic: Chemistry, d and f Block Elements, NEET
Why does fluorine exhibit anomalous behavior in many properties?

Options:
A Due to its high ionization energy
B Due to its low electronegativity
C Due to its availability of d orbitals
D Due to its small size, high electronegativity, and low F-F bond dissociation enthalpy

The correct answer is:
Due to its small size, high electronegativity, and low F-F bond dissociation enthalpy

Solution:
The anomalous behavior of fluorine is due to its small size, high electronegativity, and low F-F bond dissociation enthalpy, among other factors.

Topic: Chemistry, p Block Elements (Group 15, 16, 17 & 18), NEET
Why does fluorine have a less negative electron gain enthalpy compared to chlorine?

Options:
A Smaller size of fluorine atom
B Greater electron affinity of fluorine
C Strong attraction in 2p orbitals of fluorine
D Larger atomic radius of fluorine

The correct answer is:
Smaller size of fluorine atom

Solution:
Fluorine has a less negative electron gain enthalpy compared to chlorine due to the smaller size of the fluorine atom, which results in strong interelectronic repulsions in its relatively small 2p orbitals. This makes the incoming electron not experience as much attraction.**

Topic: Chemistry, p Block Elements (Group 15, 16, 17 & 18), NEET
Why does fluorine not show a disproportionation reaction?

Options:
A Because it has a high electronegativity
B Because it has a high atomic number
C Because it has a stable electron configuration
D Because it has a low ionization energy

The correct answer is:
Because it has a high electronegativity

Solution:
Correct Option is : (A)
Because it has a high electronegativity

Topic: Chemistry, Redox Reactions, NEET
Why does graphite conduct electricity along the sheet?

Options:
A Because of covalent bonds
B Because of ionic bonds
C Because of van der Waals forces
D Because of delocalized electrons

The correct answer is:
Because of delocalized electrons

Solution:
Graphite conducts electricity along the sheet due to the delocalized electrons.

Topic: Chemistry, p Block Elements (Group 13 & 14), NEET
Why does hard water not form lather with soap?

Options:
A Hard water contains dissolved minerals that react with soap.
B Hard water has a higher pH, making it less effective with soap.
C Hard water has a lower surface tension, preventing lather formation.
D Hard water contains excessive amounts of detergent.

The correct answer is:
Hard water contains dissolved minerals that react with soap.

Solution:
Correct Option is : (A)
Hard water contains dissolved minerals that react with soap.

Topic: Chemistry, Hydrogen, NEET
Why does Hydrogen exhibit dual behaviour?

Options:
A Due to its unique position in the periodic table.
B Because it has both metallic and non-metallic properties.
C Because it can form both ionic and covalent compounds.
D Because of its ability to exist as both a gas and a liquid at room temperature.

The correct answer is:
Due to its unique position in the periodic table.

Solution:
Correct Option is : (A)
Due to its unique position in the periodic table.

Topic: Chemistry, Hydrogen, NEET
Why does hydrogen occur in a diatomic form rather than in a monoatomic form under normal conditions?

Options:
A Because the ionization enthalpy of hydrogen atom is very high, hence, it is very hard to remove its only electron, instead it forms a covalent bond and exists in diatomic form
B Because hydrogen has an odd number of electrons, leading to the formation of H2molecules.
C Because the diatomic form of hydrogen has a lower energy state than the monoatomic form.
D Because hydrogen's atomic size allows it to readily form H2molecules through van der Waals forces.

The correct answer is:
Because the ionization enthalpy of hydrogen atom is very high, hence, it is very hard to remove its only electron, instead it forms a covalent bond and exists in diatomic form

Solution:
Correct Option is : (A)
Because the ionization enthalpy of hydrogen atom is very high, hence, it is very hard to remove its only electron, instead it forms a covalent bond and exists in diatomic form

Topic: Chemistry, Hydrogen, NEET
Why does hydrogen peroxide have a non-planar structure?

Options:
A Due to the presence of two oxygen atoms
B Due to the presence of two hydrogen atoms
C Due to the presence of lone pairs of electrons
D Due to the absence of lone pairs of electrons

The correct answer is:
Due to the presence of lone pairs of electrons

Solution:
Hydrogen peroxide has a non-planar structure because of the presence of lone pairs of electrons on the oxygen atoms, which create repulsion and force the molecule out of planarity.

Topic: Chemistry, Hydrogen, NEET