datavorous/entrance-exam-dataset huggingface dataset:
Why is the change in pH with temperature often ignored?

Options:
A Variations in pH with temperature are not related to pKw.
B Variations in pH with temperature are significant and should not be ignored.
C Variations in pH with temperature are not relevant in chemistry.
D Variations in pH with temperature are often ignored because they are usually very small and do not significantly impact pH calculations.

The correct answer is:
Variations in pH with temperature are often ignored because they are usually very small and do not significantly impact pH calculations.

Solution:
Variations in pH with temperature are often ignored in chemistry because they are usually very small and do not significantly affect pH calculations.

Topic: Chemistry, Ionic Equilibrium, NEET
Why is the change in temperature of a system a state function?

Options:
A Because it is independent of the path taken to reach the final state.
B Because it is a property of the system at a given state.
C Both A and B
D None of the above

The correct answer is:
Both A and B

Solution:
The paragraph states that the change in temperature of a system is a state function because it is independent of the path taken to reach the final state and because it is a property of the system at a given state.

Topic: Chemistry, Thermodynamics (C), NEET
Why is the chemistry of elements succeeding the actinoids less known?

Options:
A They are highly reactive
B They are unreactive
C They have unstable isotopes
D They are affected by the actinoid contraction

The correct answer is:
They are affected by the actinoid contraction

Solution:
Actinoid contractions, have extended effects on the sizes, and therefore, the properties of the elements succeeding them in their respective periods. Thus, the chemistry of elements succeeding the actinoids are much less known at the present time.

Topic: Chemistry, d and f Block Elements, NEET
Why is the chemistry of moscovium yet to be established?

Options:
A It is too reactive to study.
B It has an extremely long half-life.
C It is not present in significant quantities.
D Its chemical properties are well known.

The correct answer is:
It is not present in significant quantities.

Solution:
The paragraph mentions that moscovium is available in very little amount, which is why its chemistry is yet to be established.

Topic: Chemistry, p Block Elements (Group 15, 16, 17 & 18), NEET
Why is the choice of starting materials important in green chemistry?

Options:
A It increases chemical pollution.
B It has no impact on the environment.
C It affects the yield of the synthesis process.
D It is irrelevant to the synthesis process.

The correct answer is:
It affects the yield of the synthesis process.

Solution:
The choice of starting materials is important in green chemistry because it can significantly impact the yield of the synthesis process and, in turn, its environmental impact.

Topic: Chemistry, Environmental Chemistry, NEET
Why is the classification based on pharmacological effect useful for doctors?

Options:
A It categorizes drugs by their color
B It provides information about drug shapes
C It helps doctors choose the right treatment for specific problems
D It classifies drugs based on their chemical composition

The correct answer is:
It helps doctors choose the right treatment for specific problems

Solution:
This classification is useful for doctors because it provides them with the whole range of drugs available for the treatment of a particular type of problem.

Topic: Chemistry, Chemistry in Everyday Life, NEET
Why is the climate of a harbour town more temperate than that of a town in a desert at the same latitude?

Options:
A Precipitation levels
B Elevation
C Ocean currents
D Relative humidity

The correct answer is:
Relative humidity

Solution:
Correct Option is : (D)
Relative humidity

Topic: Chemistry, Thermodynamics, NEET
Why is the C—O—H bond angle in alcohols slightly less than the tetrahedral angle whereas the C—O—C bond angle in ether is slightly greater?

Options:
A Ethers have less repulsion between lone pairs on oxygen and bonding pairs in the C—O—C bond, causing a larger bond angle.
B The C-O-H bond angle in alcohols is slightly less than the tetrahedral angle because of the repulsion between the two lone pairs of electrons on oxygen atoms as these pairs pushes the C-O bonds closer to each other.In case of ethers, the oxygen atom is attached to bulky alkyl groups, hence repulsion between these R groups pushes the two C-O bonds away from each other and hence the bond angle is slightly greater than the tetrahedral angle.
C Alcohols have a greater electronegativity difference between carbon and oxygen, resulting in a smaller bond angle.
D Ethers have a greater electronegativity difference between carbon and oxygen, resulting in a larger bond angle.

The correct answer is:
The C-O-H bond angle in alcohols is slightly less than the tetrahedral angle because of the repulsion between the two lone pairs of electrons on oxygen atoms as these pairs pushes the C-O bonds closer to each other.In case of ethers, the oxygen atom is attached to bulky alkyl groups, hence repulsion between these R groups pushes the two C-O bonds away from each other and hence the bond angle is slightly greater than the tetrahedral angle.

Solution:
Correct Option is : (B)
The C-O-H bond angle in alcohols is slightly less than the tetrahedral angle because of the repulsion between the two lone pairs of electrons on oxygen atoms as these pairs pushes the C-O bonds closer to each other.In case of ethers, the oxygen atom is attached to bulky alkyl groups, hence repulsion between these R groups pushes the two C-O bonds away from each other and hence the bond angle is slightly greater than the tetrahedral angle.

Topic: Chemistry, Alcohols Phenols and Ethers, NEET
Why is the concept of a "system" important in thermodynamics?

Options:
A To study microscopic properties
B To define the surroundings
C To focus observations on a specific part of the universe
D To perform chemical reactions

The correct answer is:
To focus observations on a specific part of the universe

Solution:
The concept of a "system" in thermodynamics allows scientists to focus their observations on a specific part of the universe for study.

Topic: Chemistry, Thermodynamics (C), NEET
Why is the concept of enthalpy useful in chemical reactions?

Options:
A Enthalpy is a state function, making calculations simpler.
B Enthalpy is a measure of temperature changes.
C Enthalpy is directly proportional to the volume change.
D Enthalpy is unrelated to chemical reactions.

The correct answer is:
Enthalpy is a state function, making calculations simpler.

Solution:
Enthalpy is a state function, meaning it depends only on the initial and final states of the system, making calculations more straightforward as the path taken doesn't matter.

Topic: Chemistry, Thermodynamics (C), NEET
Why is the concept of hybridisation introduced in the context of molecular geometry?

Options:
A To determine atomic weights
B To explain bond polarity
C To predict chemical reactivity
D To explain the characteristic geometrical shapes of molecules

The correct answer is:
To explain the characteristic geometrical shapes of molecules

Solution:
The concept of hybridisation is introduced to explain the characteristic geometrical shapes of molecules like CH4, NH3, and H2O.

Topic: Chemistry, Chemical Bonding and Molecular Structure, NEET
Why is the cyclic structure of benzene, with alternating single and double bonds, inadequate for explaining its properties?

Options:
A It lacks carbon atoms.
B It contains too many hydrogen atoms.
C It should exhibit two different bond lengths, but it doesn't.
D It has a linear structure.

The correct answer is:
It should exhibit two different bond lengths, but it doesn't.

Solution:
The cyclic structure of benzene should exhibit two different bond lengths due to single and double bonds, but it doesn't.

Topic: Chemistry, General Organic Chemistry, NEET
Why is the difference in electronegativity less pronounced among the heavier elements in Group 15?

Options:
A Increased metallic character
B Smaller atomic size
C Decreased electron affinity
D Similar valence electron configurations

The correct answer is:
Similar valence electron configurations

Solution:
The paragraph mentions that among the heavier elements, the difference in electronegativity is not that much pronounced, likely because they have similar valence electron configurations.

Topic: Chemistry, p Block Elements (Group 15, 16, 17 & 18), NEET
Why is the E⊖(M2+/M) value for copper positive (+0.34V)?

Options:
A Copper readily gains electrons to form M2+ions.
B Copper has a strong affinity for oxygen.
C Copper has a high value of atomization enthalpy and low hydration enthalpy. Thus, as a result, the overall effect E⊖(M2+/M) for copper is positive.
D Copper has a higher ionization energy than most other metals

The correct answer is:
Copper has a high value of atomization enthalpy and low hydration enthalpy. Thus, as a result, the overall effect E⊖(M2+/M) for copper is positive.

Solution:
Correct Option is : (C)
Copper has a high value of atomization enthalpy and low hydration enthalpy. Thus, as a result, the overall effect E⊖(M2+/M) for copper is positive.

Topic: Chemistry, d and f Block Elements, NEET
Why is the E⊖value for the Mn3+/Mn2+couple much more positive than that for Cr3+/Cr2+or Fe3+/Fe2+?

Options:
A Cr and Fe have a greater affinity for oxygen.
B due to the much larger third ionization energy of Mn (where the required change is d5to d4)
C Mn forms stronger bonds with ligands than Cr and Fe.
D Mn has a higher ionization energy than Cr and Fe.

The correct answer is:
due to the much larger third ionization energy of Mn (where the required change is d5to d4)

Solution:
Correct Option is : (B)
due to the much larger third ionization energy of Mn (where the required change is d5to d4)

Topic: Chemistry, d and f Block Elements, NEET
Why is the electron gain enthalpy of O or F less negative than that of the succeeding element (S or Cl)?

Options:
A Oxygen and fluorine have smaller atomic sizes.
B Oxygen and fluorine have lower effective nuclear charges.
C Oxygen and fluorine have higher electron-electron repulsion.
D Oxygen and fluorine have larger atomic radii.

The correct answer is:
Oxygen and fluorine have higher electron-electron repulsion.

Solution:
The electron gain enthalpy of O or F is less negative than that of the succeeding element (S or Cl) because when an electron is added to O or F, the added electron goes to the smaller n = 2 quantum level and suffers significant repulsion from the other electrons present in this level.

Topic: Chemistry, Classification of Elements and Periodicity in Properties, NEET
Why is the electrostatic field inside a conductor zero, despite the dimensions of an atom being of the order of an Angstrom, leading to large electric fields between the protons and electrons?

Options:
A The electric fields inside a conductor cancel each other out due to the movement of free electrons.
B The electrostatic field inside a conductor is shielded by the arrangement of atoms within the material.
C The excess charges on the surface of an isolated conductor distribute themselves in such a way that the net electric field inside the conductor becomes zero.
D The electrostatic field is unable to penetrate the inner structure of a conductor due to the repulsion between the excess charges and the interior atoms.

The correct answer is:
The excess charges on the surface of an isolated conductor distribute themselves in such a way that the net electric field inside the conductor becomes zero.

Solution:
Correct Option is : (C)
The excess charges on the surface of an isolated conductor distribute themselves in such a way that the net electric field inside the conductor becomes zero.

Topic: Chemistry, Electrostatics, NEET
Why is the enthalpy of adsorption in physical adsorption considered low?

Options:
A Strong covalent bonds are formed.
B The process is endothermic.
C Weak van der Waals' forces are involved.
D The process is irreversible.

The correct answer is:
Weak van der Waals' forces are involved.

Solution:
The paragraph explains that the attraction between gas molecules and the solid surface in physical adsorption is only due to weak van der Waals’ forces, leading to a low enthalpy of adsorption.

Topic: Chemistry, Surface Chemistry, NEET
Why is the ester hydrolysis slow in the beginning and becomes faster after sometime?

Options:
A The ester molecules need time to dissolve in water.
B Initially, the concentration of water is low, and as the reaction proceeds, more water becomes available.
C The ester molecules undergo a structural change over time, making them more reactive.
D The temperature increases as the reaction progresses, speeding up the hydrolysis.

The correct answer is:
Initially, the concentration of water is low, and as the reaction proceeds, more water becomes available.

Solution:
Correct Option is : (B)
Initially, the concentration of water is low, and as the reaction proceeds, more water becomes available.

Topic: Chemistry, Surface Chemistry, NEET
Why is the evolution of the C₄ photosynthetic system important in plants?

Options:
A To minimize water loss
B To maximize the availability of CO₂
C To create more efficient photosynthesis
D To increase the humidity of the rainforest

The correct answer is:
To minimize water loss

Solution:
The evolution of the C₄ photosynthetic system is important because it helps to minimize water loss in plants. C₄ plants are twice as efficient as C₃ plants in terms of fixing carbon dioxide (making sugar), but a C₄ plant loses only half as much water as a C₃ plant for the same amount of CO₂ fixed. This allows the plant to conserve water and minimize water loss.

Topic: Biology, Transport in Plants, NEET
Why is the first ionization enthalpy of Cr lower than that of Zn?

Options:
A Cr has a smaller atomic radius than Zn.
B Cr has a more stable electronic configuration.
C Cr has a higher nuclear charge than Zn.
D Cr has a higher electron affinity than Zn.

The correct answer is:
Cr has a more stable electronic configuration.

Solution:
Correct Option is : (B)
Cr has a more stable electronic configuration.

Topic: Chemistry, d and f Block Elements, NEET
Why is the first ionization enthalpy of noble gases higher than that of other elements?

Options:
A Noble gases have fewer electrons.
B Noble gases have smaller nuclei.
C Noble gases have more shielding electrons.
D Noble gases have stable electron configurations.

The correct answer is:
Noble gases have stable electron configurations.

Solution:
Noble gases have closed electron shells and very stable electron configurations, leading to higher first ionization enthalpies.

Topic: Chemistry, Classification of Elements and Periodicity in Properties, NEET
Why is the fluidity of the cell membrane important for cell functions?

Options:
A It allows for cell growth and division
B It enables the formation of intercellular junctions
C It facilitates secretion and endocytosis
D All of the above

The correct answer is:
All of the above

Solution:
The fluidity of the cell membrane is important for cell functions such as cell growth, formation of intercellular junctions, secretion, endocytosis, and cell division.

Topic: Biology, Cell - The Unit of Life, NEET
Why is the formation of Ce(IV) favored?

Options:
A It has a noble gas configuration.
B It is a strong reducing agent.
C It has a completely empty f subshell.
D It has a low ionization enthalpy.

The correct answer is:
It has a noble gas configuration.

Solution:
The formation of Ce(IV) is favored because it has a noble gas configuration.

Topic: Chemistry, d and f Block Elements, NEET
Why is the formula mass used instead of molecular mass for compounds like NaCl in the solid state?

Options:
A Because the molecular mass is too large.
B Because the molecular mass is undefined.
C Because in the solid state, the compound does not exist as a single molecule.
D Because the molecular mass is not relevant for solid compounds.

The correct answer is:
Because in the solid state, the compound does not exist as a single molecule.

Solution:
In the solid state, compounds like NaCl do not exist as single entities or molecules, which is why the formula mass is used instead of the molecular mass.

Topic: Chemistry, Some Basic Concepts of Chemistry, NEET
Why is the Friedel-Crafts alkylation reaction not suitable for the synthesis of highly branched alkylbenzenes?

Options:
A Highly branched alkylbenzenes cannot be synthesized through this reaction.
B It leads to the formation of multiple alkyl groups on the benzene ring.
C Steric hindrance limits the attachment of highly branched alkyl groups.
D The reaction is too slow for branched alkyl groups.

The correct answer is:
Steric hindrance limits the attachment of highly branched alkyl groups.

Solution:
Steric hindrance makes it difficult for highly branched alkyl groups to attach to the benzene ring in the Friedel-Crafts alkylation reaction, favoring the formation of less hindered products.

Topic: Chemistry, Hydrocarbons, NEET
Why is the 'g' subscript not used for energy levels in tetrahedral complexes?

Options:
A Tetrahedral complexes lack symmetry.
B Tetrahedral complexes have higher symmetry than octahedral complexes.
C The 'g' subscript is reserved for square planar complexes.
D Tetrahedral complexes are always in the high spin configuration.

The correct answer is:
Tetrahedral complexes lack symmetry.

Solution:
The 'g' subscript is not used for energy levels in tetrahedral complexes because tetrahedral complexes lack symmetry.

Topic: Chemistry, Coordination Compounds, NEET
Why is the green manganate paramagnetic, while the permanganate is diamagnetic?

Options:
A The manganate has an unpaired electron, while the permanganate does not.
B The manganate has a lower oxidation state of manganese.
C The manganate has a higher solubility in water.
D The manganate has a higher temperature-dependent weak paramagnetism.

The correct answer is:
The manganate has an unpaired electron, while the permanganate does not.

Solution:
The green manganate is paramagnetic because of one unpaired electron, while the permanganate is diamagnetic due to the absence of an unpaired electron.

Topic: Chemistry, d and f Block Elements, NEET
Why is the H-H bond dissociation enthalpy of dihydrogen the highest for a single bond between two atoms?

Options:
A Due to its low atomic mass
B Due to its high atomic number
C Due to its complete electronic configuration
D Due to the presence of neutrons in its nucleus

The correct answer is:
Due to its complete electronic configuration

Solution:
The H-H bond dissociation enthalpy of dihydrogen is the highest for a single bond between two atoms because of its complete electronic configuration.

Topic: Chemistry, Hydrogen, NEET
Why is the high energy required to transform Cu(s) to Cu2+(aq) not balanced by its hydration enthalpy?

Options:
A Because Cu2+(aq) is unstable
B Because Cu2+(aq) has a high hydration enthalpy
C Because Cu2+(aq) is highly soluble
D Because Cu2+(aq) has a low hydration enthalpy

The correct answer is:
Because Cu2+(aq) has a low hydration enthalpy

Solution:
The high energy to transform Cu(s) to Cu2+(aq) is not balanced by its hydration enthalpy.

Topic: Chemistry, d and f Block Elements, NEET
Why is the highest oxidation state of a metal exhibited in its oxide or fluoride only?

Options:
A because metal atoms have a stronger attraction for oxygen and fluorine compared to other elements.
B because of its small size and high electronegativity oxygen or fluorine can oxidize the metal to its highest oxidation state.
C because oxides and fluorides are the most stable compounds formed by metals.
D because oxides and fluorides have a higher electron affinity compared to other compounds.

The correct answer is:
because of its small size and high electronegativity oxygen or fluorine can oxidize the metal to its highest oxidation state.

Solution:
Correct Option is : (B)
because of its small size and high electronegativity oxygen or fluorine can oxidize the metal to its highest oxidation state.

Topic: Chemistry, d and f Block Elements, NEET
Why is the incidence of allergies and asthma increasing among children in metro cities of India?

Options:
A Due to low levels of immunity
B Due to sensitivity to the environment
C Due to lack of proper medical care
D Due to poor diet and lifestyle

The correct answer is:
Due to sensitivity to the environment

Solution:
Modern-day life style has resulted in lowering of immunity and more sensitivity to allergens – more and more children in metro cities of India suffer from allergies and asthma due to sensitivity to the environment.

Topic: Biology, Human Health and Diseases, NEET
Why is the interaction between chloride ions and Si⁴⁺ not very strong?

Options:
A Chloride ions have a strong positive charge.
B Chloride ions have a weak positive charge.
C Chloride ions have a strong negative charge.
D Chloride ions have a weak negative charge.

The correct answer is:
Chloride ions have a weak positive charge.

Solution:
Correct Option is : (B)
Chloride ions have a weak positive charge.

Topic: Chemistry, p Block Elements (Group 15, 16, 17 & 18), NEET
Why is the Ionisation enthalpy of hydrogen higher than that of sodium?

Options:
A Hydrogen has a smaller atomic size than sodium.
B Hydrogen has a greater nuclear charge than sodium.
C Hydrogen has a lower number of electrons compared to sodium.
D Hydrogen has a higher electron affinity than sodium.

The correct answer is:
Hydrogen has a greater nuclear charge than sodium.

Solution:
Correct Option is : (B)
Hydrogen has a greater nuclear charge than sodium.

Topic: Chemistry, Hydrogen, NEET
Why is the ionization enthalpy of Group 15 elements much greater than that of Group 14 elements in the corresponding periods?

Options:
A Smaller size of Group 15 elements
B Half-filled p orbitals electronic configuration
C Greater number of valence electrons
D Stronger metallic character

The correct answer is:
Half-filled p orbitals electronic configuration

Solution:
The paragraph attributes the much greater ionization enthalpy of Group 15 elements to their extra stable half-filled p orbitals electronic configuration.

Topic: Chemistry, p Block Elements (Group 15, 16, 17 & 18), NEET
Why is the ionization enthalpy of Zn2+ lower compared to Cr2+ and Cu2+?

Options:
A Zn2+ has fewer d electrons
B Zn2+ has more s electrons
C Zn2+ has a lower atomic number
D Zn2+ has more p electrons

The correct answer is:
Zn2+ has fewer d electrons

Solution:
Zn2+ has a d10 configuration, which means it has fewer d electrons compared to Cr2+ and Cu2+, leading to a lower ionization enthalpy.

Topic: Chemistry, d and f Block Elements, NEET
Why is the lanthanoid contraction associated with the filling of 4f orbitals before 5d series of elements begin?

Options:
A Because 4f orbitals have a higher shielding effect.
B Because 5d orbitals have a higher shielding effect.
C Because 4f orbitals have a lower shielding effect.
D Because 5d orbitals have a lower shielding effect.

The correct answer is:
Because 4f orbitals have a lower shielding effect.

Solution:
The lanthanoid contraction is associated with the filling of 4f orbitals before 5d series of elements begin, and this is because the shielding of one 4f electron by another is less effective.

Topic: Chemistry, d and f Block Elements, NEET