datavorous/entrance-exam-dataset huggingface dataset:
Although Cr3+and Co2+ions have the same number of unpaired electrons, the magnetic moment of Cr3+is 3.87 B.M. and that of Co2+is 4.87 B.M. Why?

Options:
A Cr3+has a higher nuclear charge than Co2+.
B Co2+has a higher spin multiplicity than Cr3+.
C Co2+has a larger ionic radius than Cr3+.
D Cr3+has a more stable electronic configuration.

The correct answer is:
Co2+has a larger ionic radius than Cr3+.

Solution:
Correct Option is : (C)
Co2+has a larger ionic radius than Cr3+.

Topic: Chemistry, d and f Block Elements, NEET
Although electron gain enthalpy of fluorine is less negative as compared to chlorine, fluorine is a stronger oxidising agent than chlorine. Why?

Options:
A Fluorine forms stronger bonds with other elements.
B Fluorine has a higher ionization energy.
C Fluorine has a higher electronegativity.
D Fluorine has a larger atomic radius.

The correct answer is:
Fluorine has a higher electronegativity.

Solution:
Correct Option is : (C)
Fluorine has a higher electronegativity.

Topic: Chemistry, p Block Elements (Group 13 & 14), NEET
Although fluorine is more electronegative than oxygen, the ability of oxygen to stabilize higher oxidation states exceeds that of fluorine. Why?

Options:
A Oxygen forms more stable covalent bonds than fluorine.
B Oxygen has a higher electron affinity than fluorine.
C Oxygen has a higher electron density than fluorine.
D Oxygen has a larger atomic size than fluorine.

The correct answer is:
Oxygen forms more stable covalent bonds than fluorine.

Solution:
Correct Option is : (A)
Oxygen forms more stable covalent bonds than fluorine.

Topic: Chemistry, d and f Block Elements, NEET
Although heat is a path function but heat absorbed by the system under certain specific conditions is independent of path. What are those conditions? Explain.

Options:
A When the system is at a constant temperature.
B When the system is undergoing a phase change.
C When the system is in a closed, adiabatic container.
D At a constant volume and at constant pressure heat change is a state function because it is equal to change in internal energy and change in enthalpy respectively which are state functions

The correct answer is:
At a constant volume and at constant pressure heat change is a state function because it is equal to change in internal energy and change in enthalpy respectively which are state functions

Solution:
Correct Option is : (D)
At a constant volume and at constant pressure heat change is a state function because it is equal to change in internal energy and change in enthalpy respectively which are state functions

Topic: Chemistry, Thermodynamics (C), NEET
Although much carbon dioxide is carried in the blood, yet blood does not become acidic because

Options:
A CO2 is continously diffused through the tissues and is not allowed to accumulate
B CO2 combines with water to form H2CO3, which is neutralized by Na2CO3
C In CO2 transport, blood buffers play an important role
D CO2 is absorbed by leucocytes

The correct answer is:
In CO2 transport, blood buffers play an important role

Solution:
Blood does not become acidic due to buffering action. Bicarbonates act as buffering agents.
H2O+ CO2â H2CO3âH++HCO3-

Topic: Biology, Breathing and Exchange of Gases, NEET
Although phenoxide ion has more number of resonating structures than carboxylate ion, carboxylic acid is a stronger acid than phenol. Why?

Options:
A The carboxylate ion is more stable due to inductive effect, which decreases its acidity compared to phenol.
B Phenol has an oxygen atom, making it less acidic than carboxylic acid.
C Carboxylic acid has two oxygen atoms that can stabilize the negative charge through resonance, making it a stronger acid.
D The resonating structures of carboxylate ion contribute more towards its stability than those of phenoxide ion. As a result, carboxylate ion is more resonance-stabilized than phenoxide ion. Hence, carboxylic acid is a stronger acid than phenol.

The correct answer is:
The resonating structures of carboxylate ion contribute more towards its stability than those of phenoxide ion. As a result, carboxylate ion is more resonance-stabilized than phenoxide ion. Hence, carboxylic acid is a stronger acid than phenol.

Solution:
Correct Option is : (D)
The resonating structures of carboxylate ion contribute more towards its stability than those of phenoxide ion. As a result, carboxylate ion is more resonance-stabilized than phenoxide ion. Hence, carboxylic acid is a stronger acid than phenol.

Topic: Chemistry, Aldehydes and Ketones, NEET
Although the geometries of NH3and H2O molecules are distorted tetrahedral, why is the bond angle in water less than that of ammonia?

Options:
A The smaller size of oxygen atoms in H2O compared to nitrogen atoms in NH3leads to stronger repulsion between lone pairs of electrons, causing a smaller bond angle in water.
B Water molecules have a higher electronegativity than ammonia molecules, which results in stronger electron-electron repulsion and a smaller bond angle.
C The oxygen-hydrogen bond in H2O is weaker than the nitrogen-hydrogen bond in NH3, leading to a greater distortion of the bond angle in water.
D The presence of two lone pairs of electrons on the oxygen atom in H2O results in greater electron-electron repulsion and a smaller bond angle compared to ammonia.

The correct answer is:
The presence of two lone pairs of electrons on the oxygen atom in H2O results in greater electron-electron repulsion and a smaller bond angle compared to ammonia.

Solution:
Correct Option is : (D)
The presence of two lone pairs of electrons on the oxygen atom in H2O results in greater electron-electron repulsion and a smaller bond angle compared to ammonia.

Topic: Chemistry, Chemical Bonding and Molecular Structure, NEET
Although Zirconium belongs to 4d and hafnium belongs to 5d transition series, they show similar physical and chemical properties because both

Options:
A belong to d-block
B have same number of electrons
C belongs to the same group of the periodic table
D have similar atomic radius

The correct answer is:
have similar atomic radius

Solution:
This is because the atomic radii of 4d and 5d transition elements are nearly same. This similarity in size Zr=160, Hf=159 pm is due to lanthanoid contraction. Because of this contraction the radius of Hf becomes nearly equal to that of Zr and as the properties of an element depends on its atomic radii they show similar properties.

Topic: Chemistry, d and f Block Elements, NEET
Although Zr belongs to 4d and Hf belongs to 5d transition series, it is quite difficult to separate them. Why?

Options:
A Zr and Hf have similar electronic configurations.
B Zr and Hf have similar atomic masses.
C Zr and Hf have similar atomic sizes.
D Zr and Hf have similar melting points.

The correct answer is:
Zr and Hf have similar atomic sizes.

Solution:
Correct Option is : (C)
Zr and Hf have similar atomic sizes.

Topic: Chemistry, d and f Block Elements, NEET
Aluminium and beryllium have some similar properties. However, the two elements differ in

Options:
A exhibiting maximum covalency in compound
B exhibiting amphoteric nature in their oxides
C forming covalent halides
D forming polymeric hydrides

The correct answer is:
exhibiting maximum covalency in compound

Solution:
Be belongs to the alkaline earth metals and its general electronic configuration is Be4→1s2 2s2. It is able to form the dispositive ion. Due to small size and high charge, it has more polarising power and it shows most covalent nature in its respective family members. Due to this slight covalent nature it forms the amphoteric oxides similar to the Al.

Bur Al belongs to the p-block element and it has ability to show its covalency 6 and form polymeric covalent compounds. But Be is very small in size, it can expand its covalency only up to 4.

Topic: Chemistry, s Block Elements, NEET
Aluminium chloride exists as dimmer, Al2Cl6 in solid state as well as in solution: of non–polar solvents such as benzene. when dissolved in water, it gives

Options:
A Al2O3+6HCl
B Al3++3Cl-
C AlOH63-+3HCl
D AlH2O6+3+3Cl-

The correct answer is:
AlH2O6+3+3Cl-

Solution:
AlCl3 is covalent but in water, it become ionic due to large hydration energy it dissociated as follows
AlCl3+6H2O⇌AlH2O63++3Cl-

Topic: Chemistry, p Block Elements (Group 13 & 14), NEET
Aluminium chloride in acidified aqueous solution forms a complex ' $A$ ', in which hybridisation state of $\mathrm{Al}$ is ' $\mathrm{B}$ '. What are ' $\mathrm{A}$ ' and ' $\mathrm{B}$ ', respectively?

Options:
A $\left[\mathrm{Al}\left(\mathrm{H}_2 \mathrm{O}\right)_6\right]^{3+}, \mathrm{sp}^3 d^2$
B $\left[\mathrm{Al}\left(\mathrm{H}_2 \mathrm{O}\right)_4\right]^{3+}, s p^3$
C $\left[\mathrm{Al}\left(\mathrm{H}_2 \mathrm{O}\right)_4\right]^{3+}, d s p^2$
D $\left[\mathrm{Al}\left(\mathrm{H}_2 \mathrm{O}\right)_6\right]^{3+}, d^2 s p^3$

The correct answer is:
$\left[\mathrm{Al}\left(\mathrm{H}_2 \mathrm{O}\right)_6\right]^{3+}, \mathrm{sp}^3 d^2$

Solution:
Aluminium chloride in acidified aqueous solution forms an octahedral complex. Aqueous solution is mostly water and when the compound is dissolved in acidified aqueous solution, the water fills its vacancies and an octahedral complex, ' $\mathrm{A}^{\prime}$ which is $\left[\mathrm{Al}\left(\mathrm{H}_2 \mathrm{O}\right)_6\right]^{3+}$ is formed.
Thus, the hybridisation state of $\mathrm{Al}$ in $\left[\mathrm{Al}\left(\mathrm{H}_2 \mathrm{O}\right)_6\right]^{3+}$ is $\mathrm{sp}^3 \mathrm{~d}^2(\mathrm{~B})$.

Topic: Chemistry, Coordination Compounds, NEET, NEET 2019 (Odisha)
Aluminium crystallizes in a cubic close-packed structure. Its metallic radius is 125 pm. What is the length of the side of the unit cell?

Options:
A 2.27 * 1022nm
B 2.29 * 1022nm
C 2.27 * 1023nm
D 0.345 nm

The correct answer is:
2.27 * 1022nm

Solution:
Correct Option is : (A)
2.27 * 1022nm

Topic: Chemistry, Solid State, NEET
Aluminium dissolves in mineral acids and aqueous alkalies and thus shows amphoteric character. A piece of aluminium foil is treated with dilute hydrochloric acid or dilute sodium hydroxide solution in a test tube and on bringing a burning matchstick near the mouth of the test tube, a pop sound indicates the evolution of hydrogen gas. The same activity when performed with concentrated nitric acid, reaction doesn’t proceed. Explain the reason.

Options:
A Nitric acid is a weaker oxidizing agent than hydrochloric acid
B Nitric acid reacts differently with aluminium due to its oxidizing properties
C Nitric acid reacts with sodium hydroxide to form an inert compound
D Nitric acid forms an insoluble compound with aluminium

The correct answer is:
Nitric acid reacts differently with aluminium due to its oxidizing properties

Solution:
Correct Option is : (B)
Nitric acid reacts differently with aluminium due to its oxidizing properties

Topic: Chemistry, p Block Elements (Group 13 & 14), NEET
Aluminium is extracted from alumina $\left(\mathrm{Al}_2 \mathrm{O}_3\right)$ by electrolysis of a molten mixture of

Options:
A $\mathrm{Al}_2 \mathrm{O}_3+\mathrm{HF}+\mathrm{NaAlF}_4$
B $\mathrm{Al}_2 \mathrm{O}_3+\mathrm{CaF}_2+\mathrm{NaAlF}_4$
C $\mathrm{Al}_2 \mathrm{O}_3+\mathrm{Na}_3 \mathrm{AlF}_6+\mathrm{CaF}_2$
D $\mathrm{Al}_2 \mathrm{O}_3+\mathrm{KF}+\mathrm{Na}_3 \mathrm{AlF}_6$

The correct answer is:
$\mathrm{Al}_2 \mathrm{O}_3+\mathrm{Na}_3 \mathrm{AlF}_6+\mathrm{CaF}_2$

Solution:
Alumina, $\mathrm{Al}_2 \mathrm{O}_3$, is a bad conductor of electricity and has very high melting point, so before subjecting to electrolysis, it is mixed with fluorspar $\left(\mathrm{CaF}_2\right)$ and cryolite $\left(\mathrm{Na}_3 \mathrm{AlF}_6\right)$, which lower its melting point and make it more conducting.

Topic: Chemistry, General Principles and Processes of Isolation of Metals, NEET, NEET 2012 (Screening)
Alveoli is the site for the gas exchange in the respiratory system of humans. Gas exchange occurs due to the gradient in the partial pressure of gases. During the process, the partial pressures of oxygen in alveoli is found to be

Options:
A Less than that in deoxygenated blood.
B More than that in oxygenated blood.
C Equal to that in atmospheric air.
D Less than that in tissues.

The correct answer is:
More than that in oxygenated blood.

Solution:
The pressure exerted by a particular gas in a mixture of gases is called partial pressure. For a smooth exchange of O2, the partial pressure of O2 must be higher in alveoli than in the blood of capillary creating a gradient for movement of gases from high to low. It must be higher than deoxygenated blood and more than in tissues. The partial pressures of oxygen and carbon dioxide at different parts of the respiratory system is as follows:

Topic: Biology, Breathing and Exchange of Gases, NEET
Amensalism can be represented as:

Options:
A Species A-; Species B0;
B Species A+; Species B+;
C Species $A(-) ;$ Species $B(-)$
D Species A+; Species B0

The correct answer is:
Species A-; Species B0;

Solution:
In amensalism one species is harmed whereas the other is unaffected. It is represented as species A(-); species B(0).

Topic: Biology, Organisms and Populations, NEET, NEET 2021
Amensalism is an association between two species where:

Options:
A one species is harmed and other is benefitted
B one species is harmed and other is unaffected
C one species is benefitted and other is unaffected
D both the species are harmed.

The correct answer is:
one species is harmed and other is unaffected

Solution:
Amensalism is an association between two species where one species is harmed and other is unaffected.

Topic: Biology, Organisms and Populations, NEET
Amine oxide, when heated, forms alkene. This reaction is called

Options:
A Cope elimination
B Curtius reaction
C Hoffmann elimination
D Mannich reaction

The correct answer is:
Cope elimination

Solution:
The Cope elimination results in an alkene and an N,N-dialkylhydroxylamine. It is elimination reaction (E2) when leaving groups are H and R2N-O- forming R2NOH .

Topic: Chemistry, Amines, NEET
Amine that cannot be prepared by Gabriel phthalimide synthesis is

Options:
A Benzyl amine
B Aniline
C iso-butylamine
D tertiary-butylamine

The correct answer is:
Aniline

Solution:
Only pure 1o amines can be prepared by Gabriel synthesis. Aniline cannot be prepared by this method as aryl halides ( C6H5Cl or C6H5Br ) cannot undergo nucleophilic substitution as cleavage of C – X bond in haloarene is quite difficult with potassium phthalimide under ordinary conditions to give N-phenyl phthalimide.

Topic: Chemistry, Amines, NEET
Amino acid sequence, in protein synthesis is decided by the sequence of:

Options:
A $r \mathrm{RNA}$
B $t \mathrm{RNA}$
C $m$ RNA
D $c$ DNA

The correct answer is:
$m$ RNA

Solution:
In the process of protein synthesis, messenger RNA is responsible for carrying the genetic code transcribed from DNA. The process is known as translation and it occurs in ribosomes.
The sequence of amino acids in a particular protein is determined by the sequence of nucleotides in m-RNA. Ribosomal RNA (rRNA) help translate the information in messenger RNA ( $m$ RNA) into protein. transfer RNA, or $t$ RNA bring amino acids to the ribosome for protein production in a specific order, and reads the codons from the messenger RNA or mRNA.

Topic: Biology, Molecular Basis of Inheritance, NEET, NEET 2006
Amino acids are the organic compounds containing an amino group and an acidic group on ________ carbon.

Options:
A beta
B alpha
C gamma
D none of these

The correct answer is:
alpha

Solution:
Amino acids are organic compounds containing an amino group and an acidic group as substituents on the same carbon i.e. the alpha carbon.

Topic: Chemistry, Biomolecules, NEET
Amino acids behave like salts rather than simple amines or carboxylic acids. Explain.

Options:
A Because in aqueous solution, the carboxyl group loses a proton and the amino group accepts a proton to form a zwitterion.
B Amino acids are ionic compounds composed of cations and anions.
C Amino acids have a high tendency to form hydrogen bonds with water molecules.
D Amino acids are naturally found in saline environments, leading to their salt-like behavior.

The correct answer is:
Because in aqueous solution, the carboxyl group loses a proton and the amino group accepts a proton to form a zwitterion.

Solution:
Correct Option is : (A)
Because in aqueous solution, the carboxyl group loses a proton and the amino group accepts a proton to form a zwitterion.

Topic: Chemistry, Biomolecules, NEET
Amino acids can be classified as α-, β-, γ-, δ- and so on depending upon the relative position of amino group with respect to carboxyl group. Which type of amino acids form polypeptide chain in proteins?

Options:
A α-amino acids
B β-amino acids
C γ-amino acids
D δ-amino acids

The correct answer is:
α-amino acids

Solution:
Correct Option is : (A)
α-amino acids

Topic: Chemistry, Biomolecules, NEET
Amino Acids have both an amino group and a carboxyl group in their structure. Which one of the following is an amino acid?

Options:
A Formic acid
B Glycerol
C Glycolic Acid
D Glycine

The correct answer is:
Glycine

Solution:
Glycine is an amino acid.

Topic: Biology, Biomolecules (B), NEET
Ammonia forms the complex ion [Cu(NH3)4]2+ with copper ions in the alkaline solutions but not in acidic solutions. What is the reason for it?

Options:
A In acidic solutions, protons coordinate with ammonia molecules forming NH4+ ions and NH3 molecules are not available
B In alkaline solutions insoluble Cu(OH)2 is precipitated which is soluble in excess of any alkali
C Copper hydroxide is an amphoteric substance
D In acidic solutions hydration protects copper ions

The correct answer is:
In acidic solutions, protons coordinate with ammonia molecules forming NH4+ ions and NH3 molecules are not available

Solution:
Ammonia forms the complex ion [Cu(NH3)4]2+ with copper ions in the alkaline solutions but not in acidic solutions as in acidic solutions, NH3 forms a bond with H+ to give NH4+ ion which does not have a lone pair on N to act as a ligand.

Topic: Chemistry, Coordination Compounds, NEET
Ammonia forms the complex ion [Cu ( NH 3 ) 4 ] 2+ with copper ions in alkaline solution but not in acidic solution. The probable reason for this is

Options:
A In acidic solution, hydration protects Cu 2+ ions
B In acidic solution, proton co-ordinates with ammonia molecules to form NH 4+ ions and NH 3 molecules are not available
C In alkaline solutions insoluble Cu ( OH ) 2 is precipitated which is soluble in excess of any alkali
D Copper hydroxide is amphoteric substance

The correct answer is:
In acidic solution, proton co-ordinates with ammonia molecules to form NH 4+ ions and NH 3 molecules are not available

Solution:
Cu2+(aq)+NH3(l)+H+(aq)âNH4+(aq)+Cu2+(aq)
In acidic solution proton coordinates with ammonia molecules to form NH 4 + does not have a lone pair and hence cannot form co-ordination compounds.
Whereas in alkaline solution NH 3 molecules are free to form the complex.

Topic: Chemistry, Coordination Compounds, NEET
Ammonia is more easy to liquefy than oxygen, then which of the following is true about oxygen as the reason for this fact?

Options:
A It has high critical temperature.
B It has low critical temperature.
C It has high bond dissociation enthalpy.
D Its electronegativity is high.

The correct answer is:
It has low critical temperature.

Solution:
Critical temperature of a gas is highest temperature at which liquifaction of the gas first occurs. The gases having higher critical temperature are easier to liquefy. Thus, as per the information given in question, the correct reason would be that oxygen has lower critical temperature than ammina.

Topic: Chemistry, States of Matter, NEET
Ammonia is used in detection of Cu2+ ion because

Options:
A aqueous solution of NH3 reacts with Cu2+ ion to form deep blue coloured complex
B NH3 reacts with Cu2+ ion to give blue precipitate of CuO
C aqueous solution of NH3 reacts with Cu2+ ion to form white coloured complex
D NH3 reacts with Cu2+ ion to give green precipitate

The correct answer is:
aqueous solution of NH3 reacts with Cu2+ ion to form deep blue coloured complex

Solution:
Ammonia is used in detection of Cu2+ ion because aqueous solution of NH3 reacts with Cu2+ ion to form deep blue coloured complex.
Cu(aq)2++4NH3(aq)â[Cu(NH3)4](aq)2+Deep blue

Topic: Chemistry, d and f Block Elements, NEET
Ammonia, urea, uric acid, carbon dioxide, water and ions like Na+, K+, Cl–, phosphate, sulfate, etc., are

Options:
A Excretory substances
B Metabolic products
C Respiratory substances
D both (a) and (b)

The correct answer is:
both (a) and (b)

Solution:
Animals accumulate ammonia, urea, uric acid, carbon dioxide, water and ions like Na+, K+, Cl–, phosphate, sulfate, etc., either by metabolic activities or by other means like excess ingestion. These substances have to be removed totally or partially.

Topic: Biology, Excretory Products and their Elimination, NEET
Ammonium compound which on heating does not give NH3 is

Options:
A NH4NO2
B (NH4)2CO3
C (NH4)SO4
D NH4Cl

The correct answer is:
NH4NO2

Solution:
NH4NO2 does not give NH3 on heating
NH4NO2→ΔN2+2H2O
B. (NH4)2CO3→Δ2NH3+H2O+CO2
C. (NH4)2SO4→Δ2NH3+H2SO4
D. NH4Cl→ΔNH3+HCl

Topic: Chemistry, p Block Elements (Group 15, 16, 17 & 18), NEET
Ammonium dichromate on heating gives

Options:
A NO
B N2O
C NO2
D N2

The correct answer is:
N2

Solution:
Ammonium dichromate on heating gives nitrogen as follows
(NH 4 ) 2 Cr 2 O 7 → Δ N 2  +  Cr 2 O 3 Green  +  4H 2 O

Topic: Chemistry, d and f Block Elements, NEET
Ammonium dichromate on heating gives

Options:
A N 2 O
B (NH4)2CrO4
C CrO3
D Cr2O3

The correct answer is:
Cr2O3

Solution:
Ammonium dichromate on heating gives nitrogen and Cr2O3 as follows
(NH 4 ) 2 Cr 2 O 7 → Cr 2 O 3 Green + N 2 + 4H 2 O

Topic: Chemistry, d and f Block Elements, NEET
Amniocentesis involves the analysis of

Options:
A Amnion
B Body fluid of amniotes
C Amino acids of protein
D Amniotic fluid

The correct answer is:
Amniotic fluid

Solution:
Amniocentesis involves the analysis of Amniotic fluid is withdrawn. It contains foetal skin cells and a number of proteins especially enzymes. The cells can be cultured in vitro for further examination.

Topic: Biology, Reproductive Health, NEET
Amniocentesis is used for determining:

Options:
A Heart disease of the embryo
B Brain disease of the embryo
C Hereditary disease of the embryo
D All of the above

The correct answer is:
Hereditary disease of the embryo

Solution:
Amniocentesis is a withdrawal of a sample of the fluid (amniotic fluid) surrounding an embryo in the uterus by piercing the amniotic sac through the abdominal wall. As the amniotic fluid contains cells from the embryo (mostly shed from the skin), cells cultures enable chromosome patterns to be studied so that prenatal diagnosis of chromosomal abnormalities (such as Down's syndrome) can be made, Metabolic errors and other diseases, such as spina bifida, can also be diagnosed prenatally from the biochemistry of the cells or that of the fluid

Topic: Biology, Reproductive Health, NEET
Amniocentesis is used for determining

Options:
A Heart disease
B Brain disease
C The hereditary disease of the embryo
D All of the above

The correct answer is:
The hereditary disease of the embryo

Solution:
Karyotypic studies of somatic cells are done to determine abnormalities due to change in chromosome numbers, e.g. Down's syndrome, Turner's syndrome, etc. By enzyme analysis, metabolic disorders like phenylketonuria, alkaptonuria, etc, can be detected. It is a prenatal diagnostic technique.

Topic: Biology, Reproductive Health, NEET
Amnion helps in

Options:
A Exchange of gases and respiration in the foetus
B Excretion of waste material produced by the foetus
C Provide nourishment to the foetus
D Protection of the foetus from mechanical shock

The correct answer is:
Protection of the foetus from mechanical shock

Solution:
Amnion provides a kind of private aquarium to the embryo and protects it from mechanical shock and desiccation.

Topic: Biology, Human Reproduction, NEET