datavorous/entrance-exam-dataset huggingface dataset:
Explain why can alkali and alkaline earth metals not be obtained by chemical reduction methods?

Options:
A Because alkali and alkaline earth metals are highly reactive and readily react with reducing agents.
B Because alkali and alkaline earth metals have low ionization energies, making them difficult to reduce chemically.
C Because alkali and alkaline earth metals have high ionization energies, making them difficult to reduce chemically.
D Because alkali and alkaline earth metals have high melting points, making them difficult to reduce chemically.

The correct answer is:
Because alkali and alkaline earth metals are highly reactive and readily react with reducing agents.

Solution:
Correct Option is : (A)
Because alkali and alkaline earth metals are highly reactive and readily react with reducing agents.

Topic: Chemistry, s Block Elements, NEET
Explain why (CH3)3C+is more stable than CH3CH2+?

Options:
A Hyperconjugation interaction in (CH3)3C+is greater than in CH3CH2+as the (CH3)3C+has nine C-H bonds.
B (CH3)3C+is more stable because it has a lower degree of hyperconjugation due to the presence of three methyl groups (CH3), which can withdraw electron density, reducing the positive charge on the carbon atom.
C (CH3)3C+is more stable because it has a greater number of pi bonds, which increases electron delocalization and stabilizes the positive charge.
D (CH3)3C+is more stable because it has a higher molecular weight, leading to stronger van der Waals forces and greater stability.

The correct answer is:
Hyperconjugation interaction in (CH3)3C+is greater than in CH3CH2+as the (CH3)3C+has nine C-H bonds.

Solution:
Correct Option is : (A)
Hyperconjugation interaction in (CH3)3C+is greater than in CH3CH2+as the (CH3)3C+has nine C-H bonds.

Topic: Chemistry, General Organic Chemistry, NEET
Explain why despite nearly the same electronegativity, nitrogen forms hydrogen bonding while chlorine does not.

Options:
A Nitrogen has a higher atomic number.
B Nitrogen has a smaller atomic radius.
C Nitrogen forms a diatomic molecule, enhancing its bonding ability.
D Nitrogen has a higher ionization energy.

The correct answer is:
Nitrogen has a smaller atomic radius.

Solution:
Correct Option is : (B)
Nitrogen has a smaller atomic radius.

Topic: Chemistry, p Block Elements (Group 13 & 14), NEET
Explain why does conductivity of germanium crystals increase on doping with galium.

Options:
A Because Galium atom has only three valence electrons. Therefore, fourth valency of nearby germanium atom is not satisfied. Electron from neighbouring atom comes and fills the gap, thereby creating a hole in its original position. Under the influence of electric field electrons move towards positively charged plates through these holes and conduct electricity.
B Because gallium increases the density of germanium crystals.
C Because the atomic size of gallium is smaller than that of germanium.
D Because gallium changes the colour of germanium crystals.

The correct answer is:
Because Galium atom has only three valence electrons. Therefore, fourth valency of nearby germanium atom is not satisfied. Electron from neighbouring atom comes and fills the gap, thereby creating a hole in its original position. Under the influence of electric field electrons move towards positively charged plates through these holes and conduct electricity.

Solution:
Correct Option is : (A)
Because Galium atom has only three valence electrons. Therefore, fourth valency of nearby germanium atom is not satisfied. Electron from neighbouring atom comes and fills the gap, thereby creating a hole in its original position. Under the influence of electric field electrons move towards positively charged plates through these holes and conduct electricity.

Topic: Chemistry, Solid State, NEET
Explain why electronegativity of elements increases on moving from left to right in the periodic table.

Options:
A Larger atomic size leads to stronger electron-electron repulsions.
B Higher nuclear charge results in a stronger attraction for electrons.
C Partially filled inner electron shell reduces affinity for additional electrons.
D Electron cloud being more diffuse makes it easier for the atom to accept an extra electron.

The correct answer is:
Higher nuclear charge results in a stronger attraction for electrons.

Solution:
Correct Option is : (B)
Higher nuclear charge results in a stronger attraction for electrons.

Topic: Chemistry, Classification of Elements and Periodicity in Properties, NEET
Explain why fluorine forms only one oxoacid, HOF.

Options:
A Fluorine has a lower electronegativity.
B The hydrogen atom in HOF is more acidic.
C Fluorine is a weaker oxidizing agent.
D Fluorine does not readily form compounds with oxygen.

The correct answer is:
The hydrogen atom in HOF is more acidic.

Solution:
Correct Option is : (B)
The hydrogen atom in HOF is more acidic.

Topic: Chemistry, p Block Elements (Group 13 & 14), NEET
Explain why Grignard reagents should be prepared under anhydrous conditions?

Options:
A Anhydrous conditions enhance the reactivity of Grignard reagents, leading to higher yields.
B Grignard reagents are unstable in the presence of moisture and can cause explosive reactions and can also form alkenes.
C Anhydrous conditions prevent the formation of byproducts in Grignard reactions.
D Grignard reagents are insoluble in water, making anhydrous conditions necessary for their preparation.

The correct answer is:
Grignard reagents are unstable in the presence of moisture and can cause explosive reactions and can also form alkenes.

Solution:
Correct Option is : (B)
Grignard reagents are unstable in the presence of moisture and can cause explosive reactions and can also form alkenes.

Topic: Chemistry, Haloalkanes and Haloarenes, NEET
Explain why HCl is a gas and HF is a liquid.

Options:
A HCl forms stronger intermolecular hydrogen bonds than HF.
B HF molecules have higher molecular weight compared to HCl.
C HCl molecules have weaker intermolecular forces than HF.
D HF molecules have weaker intramolecular forces than HCl.

The correct answer is:
HCl molecules have weaker intermolecular forces than HF.

Solution:
Correct Option is : (C)
HCl molecules have weaker intermolecular forces than HF.

Topic: Chemistry, Hydrogen, NEET
Explain why ionisation enthalpy decreases in a group from top to bottom.

Options:
A Larger atomic size leads to stronger electron-electron repulsions.
B Lower nuclear charge results in a stronger attraction for electrons.
C Partially filled inner electron shell reduces affinity for additional electrons.
D Atomic size increases and hence force of attraction towards the outermost electron decreases.

The correct answer is:
Atomic size increases and hence force of attraction towards the outermost electron decreases.

Solution:
Correct Option is : (D)
Atomic size increases and hence force of attraction towards the outermost electron decreases.

Topic: Chemistry, Classification of Elements and Periodicity in Properties, NEET
Explain why is O=C=O nonpolar while R—O—R is polar.

Options:
A O=C=O is nonpolar because it consists of linear, symmetrical molecules with no net dipole moment whereas R—O—R is polar because it has a net dipole moment.
B O=C=O is polar because it consists of linear, unsymmetrical molecules with a net dipole moment.
C R—O—R is nonpolar because it consists of linear, symmetrical molecules with no net dipole moment.
D R—O—R is nonpolar because it consists of linear, unsymmetrical molecules with a net dipole moment.

The correct answer is:
O=C=O is nonpolar because it consists of linear, symmetrical molecules with no net dipole moment whereas R—O—R is polar because it has a net dipole moment.

Solution:
Correct Option is : (A)
O=C=O is nonpolar because it consists of linear, symmetrical molecules with no net dipole moment whereas R—O—R is polar because it has a net dipole moment.

Topic: Chemistry, Alcohols Phenols and Ethers, NEET
Explain why is ortho nitrophenol more acidic than ortho methoxyphenol?

Options:
A Ortho-nitrophenol has a larger molecular size, leading to greater acidity.
B because o-nitrophenoxide ion is stabilized due to resonance. This is not true with o-methoxyphenoxide ion. The two negative charges repel each other thereby destabilizing it.
C Ortho-methoxyphenol has a more electronegative substituent, making it less acidic.
D Ortho-methoxyphenol forms stronger hydrogen bonds with water molecules.

The correct answer is:
because o-nitrophenoxide ion is stabilized due to resonance. This is not true with o-methoxyphenoxide ion. The two negative charges repel each other thereby destabilizing it.

Solution:
Correct Option is : (B)
because o-nitrophenoxide ion is stabilized due to resonance. This is not true with o-methoxyphenoxide ion. The two negative charges repel each other thereby destabilizing it.

Topic: Chemistry, Alcohols Phenols and Ethers, NEET
Explain why Lewis acid is not required in bromination of phenol?

Options:
A Phenol is a stronger electrophile than bromine.
B Lewis acid is an electron deficient molecule. In bromination of benzene, Lewis acid is used to polarize Br2to form Br+electrophile.In case of phenol, the oxygen atom of phenol itself polarizes the bromine molecule to form Br+ion (electrophile). So, Lewis acid is not required in the bromination of phenol.
C Phenol is a strong Lewis base that can neutralize any added Lewis acid.
D Bromine is a weaker nucleophile and doesn't require a Lewis acid.

The correct answer is:
Lewis acid is an electron deficient molecule. In bromination of benzene, Lewis acid is used to polarize Br2to form Br+electrophile.In case of phenol, the oxygen atom of phenol itself polarizes the bromine molecule to form Br+ion (electrophile). So, Lewis acid is not required in the bromination of phenol.

Solution:
Correct Option is : (B)
Lewis acid is an electron deficient molecule. In bromination of benzene, Lewis acid is used to polarize Br2to form Br+electrophile.In case of phenol, the oxygen atom of phenol itself polarizes the bromine molecule to form Br+ion (electrophile). So, Lewis acid is not required in the bromination of phenol.

Topic: Chemistry, Alcohols Phenols and Ethers, NEET
Explain why low molecular mass alcohols are soluble in water.

Options:
A Low molecular mass alcohols have a high density compared to water, allowing them to mix easily.
B Low molecular mass alcohols have a low density compared to water, allowing them to float on the water surface.
C The hydrocarbon part in alcohols tends to prevent the formation of hydrogen bonds.Alcohols with lower molar mass have smaller hydrocarbon part and therefore tend to form greater hydrogen bonding and thus are more soluble in water.
D Low molecular mass alcohols are chemically inert and do not interact with water molecules.

The correct answer is:
The hydrocarbon part in alcohols tends to prevent the formation of hydrogen bonds.Alcohols with lower molar mass have smaller hydrocarbon part and therefore tend to form greater hydrogen bonding and thus are more soluble in water.

Solution:
Correct Option is : (C)
The hydrocarbon part in alcohols tends to prevent the formation of hydrogen bonds.Alcohols with lower molar mass have smaller hydrocarbon part and therefore tend to form greater hydrogen bonding and thus are more soluble in water.

Topic: Chemistry, Alcohols Phenols and Ethers, NEET
Explain why MeNH2is a stronger base than MeOH?

Options:
A Nitrogen is less electronegative than oxygen therefore lone pair of electrons on nitrogen is readily available for donation. Hence, MeNH2is more basic than MeOH.
B MeNH2contains a more electronegative atom than MeOH.
C MeNH2is a larger molecule, and larger molecules tend to be stronger bases.
D MeNH2has a lower molecular weight than MeOH, making it a stronger base.

The correct answer is:
Nitrogen is less electronegative than oxygen therefore lone pair of electrons on nitrogen is readily available for donation. Hence, MeNH2is more basic than MeOH.

Solution:
Correct Option is : (A)
Nitrogen is less electronegative than oxygen therefore lone pair of electrons on nitrogen is readily available for donation. Hence, MeNH2is more basic than MeOH.

Topic: Chemistry, Amines, NEET
Explain why NH3is basic while BiH3is only feebly basic.

Options:
A NH3has a higher electronegativity than BiH3.
B NH3contains nitrogen, which is a more reactive element.
C NH3can form stronger hydrogen bonds.
D BiH3undergoes sp3hybridization.

The correct answer is:
NH3can form stronger hydrogen bonds.

Solution:
Correct Option is : (C)
NH3can form stronger hydrogen bonds.

Topic: Chemistry, p Block Elements (Group 13 & 14), NEET
Explain why nucleophilic substitution reactions are not very common in phenols.

Options:
A The aromatic ring in phenols is highly reactive, making it difficult for nucleophiles to attack the phenolic ring.
B Phenols are inherently unreactive compounds and do not readily undergo nucleophilic substitution reactions.
C The OH group in phenols is a strong electron donating group. As a result, electron density on the benzene ring is quite high and hence it repels nucleophiles. In other words, nucleophiles cannot attack the benzene ring and hence phenols usually do not give nucleophilic substitution reactions
D Phenols have a low electron density, making them unattractive to nucleophiles.

The correct answer is:
The OH group in phenols is a strong electron donating group. As a result, electron density on the benzene ring is quite high and hence it repels nucleophiles. In other words, nucleophiles cannot attack the benzene ring and hence phenols usually do not give nucleophilic substitution reactions

Solution:
Correct Option is : (C)
The OH group in phenols is a strong electron donating group. As a result, electron density on the benzene ring is quite high and hence it repels nucleophiles. In other words, nucleophiles cannot attack the benzene ring and hence phenols usually do not give nucleophilic substitution reactions

Topic: Chemistry, Alcohols Phenols and Ethers, NEET
Explain why p-nitrophenol is more acidic than phenol.

Options:
A The presence of an electron-withdrawing group, the -NO2group,improves the acidic strength of p-nitrophenol by stabilizing the phenoxide ion, hence para-nitrophenol is more acidic than phenol.
B p-Nitrophenol has a higher molecular weight than phenol.
C p-Nitrophenol has a lower molecular weight than phenol.
D The presence of a nitro group in p-nitrophenol destabilizes the phenoxide ion formed during deprotonation.

The correct answer is:
The presence of an electron-withdrawing group, the -NO2group,improves the acidic strength of p-nitrophenol by stabilizing the phenoxide ion, hence para-nitrophenol is more acidic than phenol.

Solution:
Correct Option is : (A)
The presence of an electron-withdrawing group, the -NO2group,improves the acidic strength of p-nitrophenol by stabilizing the phenoxide ion, hence para-nitrophenol is more acidic than phenol.

Topic: Chemistry, Alcohols Phenols and Ethers, NEET
Explain why propanol has higher boiling point than that of the hydrocarbon, butane?

Options:
A Propanol has a greater number of carbon atoms than butane, leading to stronger London dispersion forces.
B Propanol exhibit hydrogen bonding due to presence of an -OH group, while butane does not.
C Propanol has a more complex molecular structure, resulting in increased intermolecular forces.
D Propanol has a higher molecular weight than butane, leading to stronger van der Waals forces.

The correct answer is:
Propanol exhibit hydrogen bonding due to presence of an -OH group, while butane does not.

Solution:
Correct Option is : (B)
Propanol exhibit hydrogen bonding due to presence of an -OH group, while butane does not.

Topic: Chemistry, Alcohols Phenols and Ethers, NEET
Explain why sodium is less reactive than potassium.

Options:
A Sodium has a higher ionization energy than potassium.
B Sodium has a lower ionization energy than potassium.
C Sodium has a higher electronegativity than potassium.
D Sodium has a lower electronegativity than potassium.

The correct answer is:
Sodium has a higher ionization energy than potassium.

Solution:
Correct Option is : (A)
Sodium has a higher ionization energy than potassium.

Topic: Chemistry, s Block Elements, NEET
Explain why sometimes foaming is seen in river water near the place where sewage water is poured after treatment?

Options:
A Detergents persist in water even after sewage treatment and cause foaming in river water.
B The foam is a natural occurrence in clean river water.
C The foam results from the increased oxygen levels in the treated sewage water.
D The foam is due to the presence of dissolved gases in the river water.

The correct answer is:
Detergents persist in water even after sewage treatment and cause foaming in river water.

Solution:
Correct Option is : (A)
Detergents persist in water even after sewage treatment and cause foaming in river water.

Topic: Chemistry, Chemistry in Everyday Life, NEET
Explain why the BeH2molecule has a zero dipole moment although the Be–H bonds are polar.

Options:
A BeH2has a zero dipole moment because the electronegativity of hydrogen is greater than that of beryllium, resulting in equal and opposite bond dipoles that cancel out.
B BeH2has a zero dipole moment because it is a linear molecule, and the bond dipoles point in opposite directions, effectively canceling each other.
C BeH2has a zero dipole moment because it is an ionic compound with no bond dipoles.
D BeH2has a zero dipole moment because the bond angles in the molecule result in a symmetrical charge distribution.

The correct answer is:
BeH2has a zero dipole moment because it is a linear molecule, and the bond dipoles point in opposite directions, effectively canceling each other.

Solution:
Correct Option is : (B)
BeH2has a zero dipole moment because it is a linear molecule, and the bond dipoles point in opposite directions, effectively canceling each other.

Topic: Chemistry, Chemical Bonding and Molecular Structure, NEET
Explain why the color of KMnO4disappears when oxalic acid is added to its solution in acidic medium.

Options:
A Oxalic acid reduces Mn(VII) to Mn(II), resulting in a colorless solution.
B Oxalic acid oxidizes Mn(VII) to Mn(IV), resulting in a colorless solution.
C Oxalic acid reacts with KMnO4to form a colorless compound.
D Oxalic acid forms a complex with KMnO4, masking its color.

The correct answer is:
Oxalic acid oxidizes Mn(VII) to Mn(IV), resulting in a colorless solution.

Solution:
Correct Option is : (B)
Oxalic acid oxidizes Mn(VII) to Mn(IV), resulting in a colorless solution.

Topic: Chemistry, d and f Block Elements, NEET
Explain why the dipole moment of chlorobenzene is lower than that of cyclohexyl chloride?

Options:
A In chlorobenzene, the Cl-atom is linked to a sp2hybridized carbon atom.In cyclohexyl chloride,the Cl-atom is linked to a sp3hybridized carbon atom. Now, the sp2hybridized carbon has more s-character than the sp3hybridized carbon atom.Moreover, the R effect of the benzene ring of chlorobenzene decreases the electron density of the C−Cl bond near the Cl-atom.Hence, the dipole moment of chlorobenzene is lower than that of cyclohexyl chloride.
B Chlorobenzene has a greater electron density around the chlorine atom due to resonance, reducing the overall dipole moment.
C Chlorobenzene has a smaller molecular mass compared to cyclohexyl chloride, resulting in a lower dipole moment.
D Chlorobenzene forms a stronger hydrogen bond with itself, reducing its overall dipole moment compared to cyclohexyl chloride.

The correct answer is:
In chlorobenzene, the Cl-atom is linked to a sp2hybridized carbon atom.In cyclohexyl chloride,the Cl-atom is linked to a sp3hybridized carbon atom. Now, the sp2hybridized carbon has more s-character than the sp3hybridized carbon atom.Moreover, the R effect of the benzene ring of chlorobenzene decreases the electron density of the C−Cl bond near the Cl-atom.Hence, the dipole moment of chlorobenzene is lower than that of cyclohexyl chloride.

Solution:
Correct Option is : (A)
In chlorobenzene, the Cl-atom is linked to a sp2hybridized carbon atom.In cyclohexyl chloride,the Cl-atom is linked to a sp3hybridized carbon atom. Now, the sp2hybridized carbon has more s-character than the sp3hybridized carbon atom.Moreover, the R effect of the benzene ring of chlorobenzene decreases the electron density of the C−Cl bond near the Cl-atom.Hence, the dipole moment of chlorobenzene is lower than that of cyclohexyl chloride.

Topic: Chemistry, Haloalkanes and Haloarenes, NEET
Explain why the electron gain enthalpy of fluorine is less negative than that of chlorine?

Options:
A Fluorine has a smaller atomic size, leading to stronger electron-electron repulsions.
B Chlorine has a higher nuclear charge, resulting in a stronger attraction for electrons.
C Fluorine has a completely filled inner electron shell, reducing its affinity for additional electrons.
D Chlorine's electron cloud is more diffuse, making it easier for the atom to accept an extra electron.

The correct answer is:
Chlorine has a higher nuclear charge, resulting in a stronger attraction for electrons.

Solution:
Correct Option is : (B)
Chlorine has a higher nuclear charge, resulting in a stronger attraction for electrons.

Topic: Chemistry, Classification of Elements and Periodicity in Properties, NEET
Explain why the following compounds behave as Lewis acids? AlCl₃

Options:
A Accepts electron pairs from Lewis bases
B Donates electron pairs to Lewis bases
C Acts as a proton acceptor
D Acts as a proton donor

The correct answer is:
Accepts electron pairs from Lewis bases

Solution:
Correct Option is : (A)
Accepts electron pairs from Lewis bases

Topic: Chemistry, p Block Elements (Group 13 & 14), NEET
Explain why the following compounds behave as Lewis acids? BCl₃

Options:
A Accepts electron pairs from Lewis bases
B Donates electron pairs to Lewis bases
C Acts as a proton acceptor
D Acts as a proton donor

The correct answer is:
Accepts electron pairs from Lewis bases

Solution:
Correct Option is : (A)
Accepts electron pairs from Lewis bases

Topic: Chemistry, p Block Elements (Group 13 & 14), NEET
Explain why the following systems are not aromatic -

Options:
A Due to them being closed conjugated systems
B Due to lack of delocalisation of (4n+2) π electrons in the cyclic system as none of the compounds are planar.
C All the compounds are aromatic
D Due to delocalisation of (4n+2) π electrons in the cyclic system all the compounds are planar.

The correct answer is:
Due to lack of delocalisation of (4n+2) π electrons in the cyclic system as none of the compounds are planar.

Solution:
Correct Option is : (B)
Due to lack of delocalisation of (4n+2) π electrons in the cyclic system as none of the compounds are planar.

Topic: Chemistry, Hydrocarbons, NEET
Explain why the following two structures, I and II cannot be the major contributors to the real structure of CH3COOCH3.

Options:
A because both structures are highly stable
B because one oxygen atom has a negative charge in both the structures
C because they are most important resonance contributors
D The two structures are less important contributors as they involve charge separation. Additionally, structure I contains a carbon atom with an incomplete octet.

The correct answer is:
The two structures are less important contributors as they involve charge separation. Additionally, structure I contains a carbon atom with an incomplete octet.

Solution:
Correct Option is : (D)
The two structures are less important contributors as they involve charge separation. Additionally, structure I contains a carbon atom with an incomplete octet.

Topic: Chemistry, General Organic Chemistry, NEET