datavorous/entrance-exam-dataset huggingface dataset:
Which of the following is not essential amino acid

Options:
A Valine
B Lysine
C Histidine
D Glycine

The correct answer is:
Glycine

Solution:
Essential amino acids cannot be made by the body. As a result, they must come from food. The 9 essential amino acids are histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, and valine.
Hence, Glycine is not an essential amino acid.

Topic: Chemistry, Biomolecules, JEE Main
Which of the following is not expected to be a ligand?

Options:
A O2-
B NO+
C NH4+
D CO

The correct answer is:
NH4+

Solution:
NH4+ does not have lone pair of electrons to donate.

Topic: Chemistry, Coordination Compounds, JEE Main
Which of the following is not formed by the reaction of $\mathrm{Cl}_2$ on $\mathrm{CH}_4$ in sunlight

Options:
A $\mathrm{CHCl}_3$
B $\mathrm{CH}_3 \mathrm{Cl}$
C $\mathrm{CH}_3 \mathrm{CH}_3$
D $\mathrm{CH}_3 \mathrm{CH}_2 \mathrm{CH}_3$

The correct answer is:
$\mathrm{CH}_3 \mathrm{CH}_2 \mathrm{CH}_3$

Solution:
$\mathrm{CH}_4 \xrightarrow{\mathrm{Cl}_2} \mathrm{CH}_3 \mathrm{Cl} \xrightarrow{\mathrm{Cl}_2} \mathrm{CH}_2 \mathrm{Cl}_2 \xrightarrow{\mathrm{Cl}_2}$ $\mathrm{CHCl}_3 \xrightarrow{\mathrm{Cl}_2} \mathrm{CCl}_4$
Since this reaction takes place by free radical mechanism. Hence, there is a possibility of formation of ethane.

Topic: Chemistry, Hydrocarbons, JEE Main
Which of the following is not formed in iodoform reaction?

Options:
A CH3COCH2I
B ICH2COCH2I
C CH3COCHI2
D CH3COCI3

The correct answer is:
ICH2COCH2I

Solution:
Halogenation of ketones or aldehydes takes place in α -position. Further presence of halogen on a carbon atom increases acidity of that particular carbon atom, hence further halogenation takes place on the carbon having halogen and not on other carbon atoms.

Topic: Chemistry, Aldehydes and Ketones, JEE Main
Which of the following is not formed when H2S reacts with acidic K2Cr2O7 solution ?

Options:
A K2SO4
B Cr2(SO4)3
C S
D CrSO4

The correct answer is:
CrSO4

Solution:
The Reaction is
K 2 Cr 2 O 7 + 4 H 2 SO 4 → K 2 SO 4 + Cr 2 SO 4 3 + 4 H 2 O + 3 O 3 O + 3 H 2 S → 3 H 2 O + 3 S
_______________________________________________________________________
K 2 Cr 2 O 7 + 4 H 2 SO 4 + 3 H 2 S → K 2 SO 4 + Cr 2 SO 4 3 + 7 H 2 O + 3 S
CrSO4 is not formed

Topic: Chemistry, d and f Block Elements, JEE Main
Which of the following is not formed when H2S reacts with acidic K2Cr2O7 solution ?

Options:
A K2SO4
B Cr2(SO4)3
C S
D CrSO4

The correct answer is:
CrSO4

Solution:
The Reaction is
K 2 Cr 2 O 7 + 4 H 2 SO 4 → K 2 SO 4 + Cr 2 SO 4 3 + 4 H 2 O + 3 O 3 O + 3 H 2 S → 3 H 2 O + 3 S
_______________________________________________________________________
K 2 Cr 2 O 7 + 4 H 2 SO 4 + 3 H 2 S → K 2 SO 4 + Cr 2 SO 4 3 + 7 H 2 O + 3 S
CrSO4 is not formed

Topic: Chemistry, d and f Block Elements, JEE Main, JEE Main 2014 (09 Apr Online)
Which of the following is not having significant/any role in maintaining counter current mechanism?

Options:
A Loop of Henle
B Vasa recta
C Sodium, urea and water
D PCT

The correct answer is:
PCT

Solution:
Mechanism of concentration of urine: Counter current mechanism
Mammals possess the ability to produce concentrated urine. Structures responsible for the concentration of urine: 1. Henle's loop. 2. Vasa recta.
The increasing osmolarity towards the inner medullary interstitium (from 300 to about 1200 mOsmol L–1) is maintained by the proximity between the Henle's loop and vasa recta and the counter-currents within themselves. The mentioned gradient is mainly developed due to NaCl and urea.

Topic: Biology, Excretory Products and their Elimination, NEET
Which of the following is not isostructural with SiCl4?

Options:
A SO42-
B PO43-
C NH4+
D SCl4

The correct answer is:
SCl4

Solution:
In SiCl4 there is sp3 hybridisation so the structure is tetrahedral. In SO42-, PO43-, NH4+ the structure is tetrahedral because in all hybridization is sp3. But in SCl4, sp3d hydridisation is present so shape is different which is see saw.

Topic: Chemistry, Chemical Bonding and Molecular Structure, JEE Main
Which of the following is not known ?

Options:
A $\mathrm{NCl}_5$
B $\mathrm{NI}_3$
C $\mathrm{SbCl}_3$
D $\mathrm{NCl}_3$

The correct answer is:
$\mathrm{NCl}_5$

Solution:
$\mathrm{NCl}_5$ is not known because of absence of $d$-orbitals in nitrogen.

Topic: Chemistry, p Block Elements (Group 15, 16, 17 & 18), JEE Main
Which of the following is not optically active ?

Options:
A Coen33+
B Crox33-
C cis-CoCl2en2+
D trans-CoCl2en2+

The correct answer is:
trans-CoCl2en2+

Solution:
trans complex is symmetrical ( has plane of symmetry)and is optically inactive.

Topic: Chemistry, Coordination Compounds, JEE Main
Which of the following is not paramagnetic

Options:
A $\mathrm{O}_2$
B $\mathrm{O}_2^{2+}$
C $\mathrm{O}_2^{2-}$
D $\mathrm{O}_2^{-}$

The correct answer is:
$\mathrm{O}_2^{2-}$

Solution:
Species with unpaired electrons is paramagnetic $O_2$ has 2 unpaired electrons, $O_2^{-}$has one unpaired, $O_2^{2-}$ has zero unpaired electrons, $\mathrm{O}_2^{2+}$ has one unpaired.

Topic: Chemistry, Chemical Bonding and Molecular Structure, JEE Main
Which of the following is not paramagnetic

Options:
A $S^{-2}$
B $\mathrm{N}_2{ }^{-}$
C $\mathrm{O}_2^{-}$
D NO

The correct answer is:
$S^{-2}$

Solution:
$S^{-2}$ have all paired electrons so it is diamagnetic.

Topic: Chemistry, Chemical Bonding and Molecular Structure, JEE Main
Which of the following is not permissible arrangement of electrons in an atom ?

Options:
A $\mathrm{n}=3, l=2, \mathrm{~m}=-3, \mathrm{~s}=-\frac{1}{2}$
B $\mathrm{n}=4, l=0, \mathrm{~m}=0, \mathrm{~s}=-\frac{1}{2}$
C $\mathrm{n}=5, l=3, \mathrm{~m}=0, \mathrm{~s}=+\frac{1}{2}$
D $\mathrm{n}=3, l=2, \mathrm{~m}=-3, \mathrm{~s}=-\frac{1}{2}$

The correct answer is:
$\mathrm{n}=3, l=2, \mathrm{~m}=-3, \mathrm{~s}=-\frac{1}{2}$

Solution:
m value $-l$ to $+l$

Topic: Chemistry, Structure of Atom, NEET, NEET 2009 (Mains)
Which of the following is not permissible arrangement of electrons in an atom?

Options:
A \(n =5, l=3, m=0, s=+\frac{1}{2} \)
B \(n =3, \mathrm{l}=2, \mathrm{~m}=-3, \mathrm{~s}=-\frac{1}{2} \)
C \(n =3, \mathrm{l}=2, \mathrm{~m}=-2, \mathrm{~s}=-\frac{1}{2} \)
D \(n =4, l=0, m=0, s=-\frac{1}{2} \)

The correct answer is:
\(n =3, \mathrm{l}=2, \mathrm{~m}=-3, \mathrm{~s}=-\frac{1}{2} \)

Solution:
The possible values of azimuthal quantum number for a particular shell are from 0 to (n-1).

The possible values of magnetic quantum number for a particular sub-shell are from -l to +l.

When, ℓ=2, m can have values -2, -1, 0, +1 & +2 m≠-3

The possible values of spin quantum number are ±12.

Topic: Chemistry, Structure of Atom, JEE Main
Which of the following is not precipitated as sulphide by passing $\mathrm{H}_2 \mathrm{~S}$ in presence of conc. $\mathrm{HCl}$

Options:
A Copper
B Arsenic
C Cadmium
D Lead

The correct answer is:
Cadmium

Solution:
$\mathrm{Cd}^{2+}$ is not precipitated by $\mathrm{H}_2 \mathrm{~S}$ in concentrated acid solution that is why the solution is diluted before passing $\mathrm{H}_2 \mathrm{~S}$ through it.

Topic: Chemistry, Practical Chemistry, JEE Main
Which of the following is not the example of uniform circular motion?

Options:
A Motion of an artificial satellite orbiting the Earth
B The motion of electrons around its nucleus
C The motion of blades of the windmills
D a person jogging in the park

The correct answer is:
a person jogging in the park

Solution:
- The motion of the body is said to be a uniform motion if it moves with constant velocity.
- Accelerated motions are non-uniform motions.
- A jogger in the park may accelerate himself or de-accelerate him and thus it changes its velocity during its motion.
- Hence the motion of a freely jogging man is not an example of uniform circular motion.

Topic: Physics, Laws of Motion, JEE Main
Which of the following is not the function of parathormone (PTH)?

Options:
A Increases calcium level in blood
B Decreases the reabsorption of calcium from the renal tubules
C Increases the calcium absorption from GIT
D Decreases the movement of calcium to bones.

The correct answer is:
Decreases the reabsorption of calcium from the renal tubules

Solution:
Functions of the parathyroid hormone (PTH) includes:
A. PTH increases the process of bone resorption or dissolution (demineralization) of bone.
B. PTH stimulates the reabsorption of Ca2+ by the renal tubules.
C. PTH increases the absorption of Ca2+ from digested food.
D. All of the above actions of PTH increase the blood Ca2+ levels, thus PTH is a hypercalcemic hormone. PTH and Thyrocalcitonin play a significant role in maintaining the calcium balance in the body.

Topic: Biology, Chemical Coordination and Integration, NEET
Which of the following is not the one of the main step in metal extraction

Options:
A Crushing and Grinding
B Concentration
C Refining of the metal
D Sedimentation

The correct answer is:
Sedimentation

Solution:
Correct Option is 4 Sedimentation
The extraction of a pure metal from its ore is called metallurgy. Inorderto extract the metal from ores, several physical and chemical methods are used. The method used depending upon chemical properties and nature of the ore from which it is to be extracted. It involves four main steps,
(1) Crushing and grinding of the ore.
(2) Concentration or dressing of the ore.
(3) Reduction to free metal.
(4) Purification or refining of the metal.

Topic: Chemistry, General Principles and Processes of Isolation of Metals, JEE Main
Which of the following is not the unit of energy?

Options:
A watt - hour
B electron - volt
C \( \mathrm{N} \mathrm{m} \)
D \( \mathrm{m}^{2} \mathrm{~s}^{-2} \)

The correct answer is:
\( \mathrm{N} \mathrm{m} \)

Solution:
Energy is known as the capacity of performing work. It can occur in various possible ways, including kinetic, potential, chemical, electrical, thermal, radioactive, or other forms such as energy in the transition process through one body to the other i.e., work and heat.

The different units of energy in different unit systems are: Joule in S.I and MKS, Erg in CGS.

As we know, 1 Joule=1 kg m2 s-2.

Energy is also expressed as E=Power×time. Here, the unit of power is Watt and that of time is hour. Thus, its other unit will be =Watt-hour. It is equal to 1 Watt of output for 1 hour.

The quantity of kinetic energy obtained from a single electron accelerated from rest by an electrical potential gap in vacuum of one volt is an electron volt.

Work is expressed as W=Force Newton×displacement metre. Thus, the unit of work is Newton×metre=N m.
In general N m is used as unit of torque. Though it is dimensionally correct, we don't use it as unit of energy.

Topic: Physics, Units and Dimensions, JEE Main
Which of the following is not the use of Salt Bridge-

Options:
A to maintain electrical neutrality
B prevents the diffusion of solution
C provides a free path for the migration of ions
D It accumulates charges

The correct answer is:
It accumulates charges

Solution:
Correct Option is : 4
It accumulates charges

Topic: Chemistry, Electrochemistry, NEET
Which of the following is not true

Options:
A Every skew-symmetric matrix of odd order is non-singular
B If determinant of a square matrix is non-zero, then it is non singular
C Adjoint of symmetric matrix is symmetric
D Adjoint of a diagonal matrix is diagonal

The correct answer is:
Every skew-symmetric matrix of odd order is non-singular

Solution:
Every skew symmetric matrix of odd order is singular. So option (1) is incorrect.

Topic: Mathematics, Matrices, JEE Main
Which of the following is not true about the denaturation of protein?

Options:
A $2^{\circ}$ structure get destroyed
B $3^{\circ}$ structure get destroyed
C $1^{\circ}$ structure get destroyed
D Bioactivity is lost

The correct answer is:
$1^{\circ}$ structure get destroyed

Solution:
During denaturation of proteins, their primary structure remains unaffected. But their secondary and tertiary structures are destroyed. The covalent bonds are broken and interaction between amino acid chains are also lost. As a result, the biological activity of the proteins is lost.

Topic: Chemistry, Biomolecules, JEE Main
Which of the following is not true about the denaturation of protein?

Options:
A $2^{\circ}$ structure get destroyed
B $3^{\circ}$ structure get destroyed
C $1^{\circ}$ structure get destroyed
D Bioactivity is lost

The correct answer is:
$1^{\circ}$ structure get destroyed

Solution:
During denaturation of proteins, their primary structure remains unaffected. But their secondary and tertiary structures are destroyed. The covalent bonds are broken and interaction between amino acid chains are also lost. As a result, the biological activity of the proteins is lost.

Topic: Chemistry, Biomolecules, AP EAMCET, AP EAMCET 2022 (06 Jul Shift 2)
Which of the following is not true about the S phase?

Options:
A DNA and histones are synthesized
B Amount of DNA per cell become half
C Even after S phase chromosome number become double
D All are true

The correct answer is:
DNA and histones are synthesized

Solution:
S-phase (synthesis phase) is the part of the cell cycle in which DNA is replicated, occurring between the G1 phase and the G2 phase. It is characterized by: DNA and histones are synthesized and DNA content gets doubled. DNA replicates in a semi-conservative manner.
The amount of DNA per cell becomes double even after S phase chromosome number remains the same.

Topic: Biology, Cell Cycle and Cell Division, NEET
Which of the following is not true about the stomach in humans?

Options:
A Oesophagus opens in cardiac part of stomach.
B Pepsin is the proteolytic enzyme of stomach.
C Rennin is the proteolytic enzyme in gastric juice of infants.
D The secretion of gastric glands does not have lipases

The correct answer is:
The secretion of gastric glands does not have lipases

Solution:
Food remains in the stomach for 4–5 hours. During this time, it mixes thoroughly with the acidic gastric juice by the churning movements of the muscular wall of the stomach and is now called the chyme.
Digestion in the stomach:
A. Proenzyme pepsinogen -----(HCl)---- → Pepsin (active enzyme).
B. Proteins ------- (Pepsin, pH = 1.8) ---- → Proteoses and peptones (peptides).
C. Rennin (a proteolytic enzyme in gastric juice of infants) helps in the digestion of milk proteins.
D. Lipases are also secreted in small amounts.

Topic: Biology, Digestion and Absorption, NEET
Which of the following is not true about vectors A→,B→ and C→?

Options:
A A→·A→B→·C→ is a scalar value.
B A→×B→·B→×C→ is a scalar value.
C A→×C→×B→×C→ is a scalar value.
D A→×B→×C→ is a vector value.

The correct answer is:
A→×C→×B→×C→ is a scalar value.

Solution:
Dot/Scalar product of two vectors gives scalar result. Cross/Vector product will give vector result.

Case: A→·A→B→·C→

Both left & right part will be a scalar value and hence its product will also be a scalar value.

Case: A→×B→·B→×C→

Both left and right part will be a vector, and then these two vectors will undergo dot product and the result will be a scalar value.

Case: A→×C→×B→×C→

Both left and right part will be a vector, and then these two vectors will undergo cross product and the result will be a vector value.

Case: A→×B→×C→

Both left and right part will be a vector, and then these two vectors will undergo cross product and the result will be a vector value.

Topic: Physics, Mathematics in Physics, JEE Main
Which of the following is not true for concentrated $\mathrm{H}_{2} \mathrm{SO}_{4}$ ?

Options:
A Sulphonating agent
B Oxidising agent
C Dehydrating agent
D Deliquescent in nature

The correct answer is:
Sulphonating agent

Solution:
Sulphuric acid $\left(\mathrm{H}_{2} \mathrm{SO}_{4}\right)$ is hygroscopic in nature, it absorbs atmospheric moisture without changing physical state. It is not deliquescent in nature.
$\therefore$ Option (a) is not true.

Topic: Chemistry, p Block Elements (Group 15, 16, 17 & 18), JEE Main
Which of the following is not true for metal carbonyls

Options:
A The oxidation state of the metal in the carbonyls is zero
B The secondary carbonyls are obtained from photo-decomposition
C Metal carbonyls are single bonded species
D $d \pi-p \pi$ overlap is observed in metal carbonyls

The correct answer is:
$d \pi-p \pi$ overlap is observed in metal carbonyls

Solution:
Metal carbonyls does not show overlapping.

Topic: Chemistry, Coordination Compounds, JEE Main
Which of the following is NOT true for metal carbonyls?

Options:
A The oxidation state of the metal in the carbonyls can be zero.
B \( \mathrm{M}-\mathrm{C} \pi \) bond is formed by back-bonding from metal to carbon
C Metal carbonyls have single bond between metal and carbon
D \( \mathrm{d} \pi-\mathrm{p} \pi \) overlap is observed in metal carbonyls.

The correct answer is:
Metal carbonyls have single bond between metal and carbon

Solution:
Metal carbonyls have synergic bond between metal and carbon in which there is a dπ-pπ back-bond from the central metal. Therefore, the M-C bond acquires a partial double bond character. Metal carbonyls usually have zero or negative oxidation states for metals.

Topic: Chemistry, Coordination Compounds, JEE Main
Which of the following is not true if \( \vec{A}=3 \hat{i}+4 \hat{j} \) and \( \vec{B}=6 \hat{i}+8 \hat{j} \), where \( A \& B \) are the magnitudes of \( \vec{A} \) and \( \vec{B} \) ?

Options:
A \( \vec{A} \times \vec{B}=0 \)
B \( \frac{A}{B}=\frac{1}{2} \)
C \( \vec{A} \cdot \vec{B}=48 \)
D \( A=5 \)

The correct answer is:
\( \vec{A} \cdot \vec{B}=48 \)

Solution:
Given, A→=3i^+4j^, B→=6i^+8j^ & B→=2A→

∴ A→×B→=i^j^k^340680=0

∴ A→=A=32+42=5, B→=B=62+82=10

⇒AB=510=12

∴ A→.B→=3·6+4·8=50

Topic: Mathematics, Vector Algebra, JEE Main
Which of the following is not used as a biopesticide?

Options:
A Xanthomonas Campestris
B Bacillus thringiensis
C Trichoderma harzianum
D Nuclear Polyhedral Virus (NPV)

The correct answer is:
Xanthomonas Campestris

Solution:
No Solution Available

Topic: Biology, Microbes in Human Welfare, NEET, NEET 2009 (Mains)
Which of the following is not used to construct salt bridge

Options:
A $\mathrm{CH}_3 \mathrm{COOK}$
B $\mathrm{KCl}$
C $\mathrm{NH}_4 \mathrm{NO}_3$
D $\mathrm{KNO}_3$

The correct answer is:
$\mathrm{CH}_3 \mathrm{COOK}$

Solution:
Salt bridges are used in electrochemical cells to maintain electrical neutrality between the two half-cells. They consist of a U-shaped tube filled with a saturated solution of a strong electrolyte. The electrolyte must be strong so that it dissociates completely in solution, providing a large number of mobile ions to complete the circuit.
- $\mathrm{CH}_3 \mathrm{COOK}$ (potassium acetate) is a weak electrolyte. Weak electrolytes dissociate only partially in solution, and therefore would not provide enough ions to function effectively in a salt bridge.
- $\mathrm{KCl}$ (potassium chloride), $\mathrm{NH}_4 \mathrm{NO}_3$ (ammonium nitrate), and $\mathrm{KNO}_3$ (potassium nitrate) are all strong electrolytes and are commonly used in salt bridges.

Topic: Chemistry, Electrochemistry, JEE Main
Which of the following is nucleophilic addition reaction?

Options:
A Hydrolysis of ethyl chloride by NaOH
B Purification of acetaldehyde by NaHSO3
C Alkylation of anisole
D Decarboxylation of acetic acid

The correct answer is:
Purification of acetaldehyde by NaHSO3

Solution:
Sodium hydrogen sulphite adds to aldehydes and ketones to form crystalline bisulphite addition products. The product is water soluble and can be converted back to the original carbonyl compound by treating it with dilute mineral acid or alkali. Therefore, these are useful for separation and purification of aldehydes like acetaldehydes.

Topic: Chemistry, Aldehydes and Ketones, JEE Main
Which of the following is nylon 6, 6 -

Options:
A

B

C

D

The correct answer is:

Solution:
Nylon 6, 6 is a polymer of hexamethylane diamine & adipic acid.

Topic: Chemistry, Polymers, JEE Main
Which of the following is observed in ethylene molecule

Options:
A Electromeric effect
B Inductive effect
C Homolytic fission
D None of these

The correct answer is:
Electromeric effect

Solution:

Topic: Chemistry, General Organic Chemistry, JEE Main
Which of the following is obtained by hydrogenation of benzoyl chloride in presence of $\mathrm{Pd}$ on $\mathrm{BaSO}_{4}$ ?

Options:
A Benzene
B Benzoic acid
C Benzyl alcohol
D Benzaldehyde

The correct answer is:
Benzaldehyde

Solution:
Rosenmund reduction

Topic: Chemistry, Aldehydes and Ketones, JEE Main
Which of the following is obtained product

Options:
A
B
C
D None of these

The correct answer is:

Solution:

Topic: Chemistry, Haloalkanes and Haloarenes, JEE Main
Which of the following is one of the main functions of carbohydrates in plants?

Options:
A Providing structural support to the plant in the form of cellulose.
B Regulating metabolic processes like generating chlorophyll.
C Storing and transmitting genetic information and water.
D Facilitating muscle contraction and movement.

The correct answer is:
Providing structural support to the plant in the form of cellulose.

Solution:
Correct Option is : (A)
Providing structural support to the plant in the form of cellulose.

Topic: Chemistry, Biomolecules, NEET
Which of the following is one-way flow rather than a two way or cyclic flow?

Options:
A Carbon
B Nitrogen
C Potassium
D Free energy

The correct answer is:
Free energy

Solution:
The movement and exchange of organic and inorganic matter between living and non-living component in a cyclical manner refers to nutrient cycle. These are also called as biogeochemical cycles as there is involvement of biotic and abiotic factors and chemical reactions. There are many important cycles which help in maintaining the biosphere like carbon cycle, nitrogen cycle etc.
In a typical food chain, the energy that is transferred from one trophic level to the next is always unidirectional and never forms a cyclical pattern. The main source of energy is the sun (solar energy/free energy), which is used by producers to make food and then it is consumed by consumers and so forth. The energy is never given back to the sun.

Topic: Biology, Ecosystem, NEET
Which of the following is oxidised by $\mathrm{SO}_2$

Options:
A $\mathrm{Mg}$
B $\mathrm{K}_2 \mathrm{Cr}_2 \mathrm{O}_7$
C $\mathrm{KMnO}_4$
D All of these

The correct answer is:
$\mathrm{Mg}$

Solution:
$\mathrm{SO}_2+2 \mathrm{Mg} \rightarrow 2 \mathrm{MgO}+\mathrm{S}$

Topic: Chemistry, p Block Elements (Group 15, 16, 17 & 18), JEE Main
Which of the following is paramagnetic?

Options:
A CO
B NO+
C O22-
D B2

The correct answer is:
B2

Solution:
Number of e-
CO=14, NO+=14
O22-=18, B2=10.
According to MOT,
CO:− σ1s2<σ*1s2<σ2s2<σ*2s2<π2px2=π2py2<σ2pz2
no unpaired e- so diamagnetic
B 2 :− σ1 s 2 < σ * 1 s 2 <σ2 s 2 < σ * 2 s 2 <π2 p x 1 =π2 p y 1
2 unpaired e-,so paramagnetic
O2−2:− σ1s2<σ*1s2<σ2s2<σ*2s2<σ2pz2<π2px2=π2py2<π*2px2=π*2py2
no unpaired e-, so diamagnetic
NO+:− σ1s2<σ*1s2<σ2s2<σ*2s2<π2px2=π2py2<σ2pz2
no unpaired e-, so diamagnetic.

Topic: Chemistry, Chemical Bonding and Molecular Structure, JEE Main, JEE Main 2017 (08 Apr Online)
Which of the following is paramagnetic

Options:
A ${ }^{O_2^{+}}$
B $\mathrm{CN}^{-}$
C $\mathrm{CO}$
D $\mathrm{N}_2$

The correct answer is:
${ }^{O_2^{+}}$

Solution:
B.O. $=\frac{1}{2}[10-5]=\frac{5}{2}=2.5$, paramagnetic

Topic: Chemistry, Chemical Bonding and Molecular Structure, JEE Main