datavorous/entrance-exam-dataset huggingface dataset:
Which one of the following aspects is an exclusive characteristic of living things?

Options:
A Isolated metabolic reactions occur in vitro
B Increase in mass from inside only
C Perception of events happening in the environment and their memory
D Increase in mass by accumulation of material both on surface as well as internally

The correct answer is:
Perception of events happening in the environment and their memory

Solution:
The most obvious and technically complicated feature of all living organisms is the ability to sense their surroundings or environment and to respond to these environmental stimuli which could be physical, chemical or biological.

Topic: Biology, The Living World, NEET, NEET 2011 (Mains)
Which one of the following bases is not present in DNA ?

Options:
A Quinoline
B Adenine
C Cytosine
D Thymine

The correct answer is:
Quinoline

Solution:
DNA contains Adenine, Thymine, cytosine and Guanine.

Topic: Chemistry, Biomolecules, JEE Main, JEE Main 2014 (06 Apr)
Which one of the following biomolecules is correctly characterised?

Options:
A Lecithin-A phosphorylated glyceride found in cell membrane
B Palmitic acid-An unsaturated fatty acid with 18 carbon atoms
C Adenylic acid-Adenosine with a glucose phosphate molecule
D Alanine amino acid-Contains an amino group and an acidic group anywhere in the molecule

The correct answer is:
Lecithin-A phosphorylated glyceride found in cell membrane

Solution:
Alanine is a neutral amino acid with non-cyclic hydrocarbon chain, one amino group and one carboxyl group. Palmitic acid is saturated fatty acid adenylic acid has pentose sugar in it not glucose.

Topic: Biology, Biomolecules (B), NEET, NEET 2012 (Mains)
Which one of the following bonds has the highest average bond energy ( $\mathrm{kcal} / \mathrm{mol}$

Options:
A $S=0$
B $C \equiv C$
C $C \equiv N$
D $N \equiv N$

The correct answer is:
$N \equiv N$

Solution:
We know that a single bond is weaker than a double bond similarly double bond is weaker than a triple bond. Hence \(\mathrm{C} \equiv \mathrm{N}\) and \(\mathrm{N} \equiv \mathrm{N}\) is the strongest bond (highest average bond energy).
Now, out of these two \((\mathrm{C} \equiv \mathrm{N})\) is a polar bond \(\mathrm{N} \equiv \mathrm{N}\) is a nonpolar bond and we know that the nonpolar bond will be stronger than the polar bond.
Here is the average bond energy of given bonds are,
B.E of \(\mathrm{S}=\mathrm{O}, \mathrm{C} \equiv \mathrm{C}, \mathrm{C} \equiv \mathrm{N}\) and \(\mathrm{N} \equiv \mathrm{N}\) are \(525,839,891\) and \(941 \mathrm{~kJ} / \mathrm{mol}^{-1}\) respectively.
Hence \(\mathrm{N} \equiv \mathrm{N}\) has the highest average bond energy.

Topic: Chemistry, Thermodynamics (C), JEE Main
Which one of the following Boolean expression is a tautology?

Options:
A p∨q∧~p∨~q
B p∧q∨p∧~q
C p∨q∧p∨~q
D p∨q∨~p∨~q

The correct answer is:
p∨q∨~p∨~q

Solution:
Let I=p∨q∨p∨~q

II= p∧q∨p∧~q

III= p∨q∧p∨~q

IV= p∨q∧~p∨~q

p	q	p∨q	p∧q	∼p	∼q	p∨∼q	p∧∼q	I	II	III	IV

T	T	T	T	F	F	T	F	T	T	T	F

T	F	T	F	F	T	T	T	T	T	T	T

F	T	T	F	T	F	F	F	T	F	F	T

F	F	F	F	T	T	T	F	T	F	F	F

Topic: Mathematics, Mathematical Reasoning, JEE Main, JEE Main 2019 (10 Apr Shift 1)
Which one of the following cannot be prepared from B 2 H 6 ?

Options:
A NaBH 4
B B 2 (CH 3 ) 4 H 2
C B 2 (CH 3 ) 6
D H 3 BO 3

The correct answer is:
B 2 (CH 3 ) 6

Solution:
In diborane, (B 2 H 6 ) molecule, only four terminal hydrogen atoms are replaceable. The two bridge H-atoms cannot be substituted. Hence B 2 (CH 3 ) 6 cannot be prepared from B 2 H 6 .

Topic: Chemistry, s Block Elements, JEE Main
Which one of the following cannot be used for preparation of vaccines against plague?

Options:
A Formalin-inactivated suspensions of virulent bacteria
B Avirulent live bacteria
C Synthetic capsular polysaccharide material
D Heat-killed suspensions of virulent bacteria

The correct answer is:
Synthetic capsular polysaccharide material

Solution:
Synthetic capsular polysaccharide vaccines are available for the treatment of pneumonia and meningitis. Vaccines against plague are prepared from the suspensions of attenuated or heat killed virulent bacteria or avirulent live bacteria.

Topic: Biology, Biotechnology and Its Applications, NEET, NEET 2010 (Mains)
Which one of the following cannot function as an oxidising agent?

Options:
A
$\mathrm{I}^{-}$

B
$\mathrm{S}(\mathrm{s})$

C
$\mathrm{NO}_3^{-}(\mathrm{aq})$

D
$\mathrm{Cr}_2 \mathrm{O}_7^{2-}$

The correct answer is:
$\mathrm{I}^{-}$

Solution:
If an electronegative element is in its lowest possible oxidation state in a compound or in free state. It can function as a powerful reducing agent.
e.g. I ${ }^{-}$

Topic: Chemistry, Classification of Elements and Periodicity in Properties, JEE Main, JEE Main 2013 (25 Apr Online)
Which one of the following carbonyl compounds cannot be prepared by addition of water on an alkyne in the presence of HgSO4 and H2SO4?

Options:
A
B
C
D

The correct answer is:

Solution:
Reaction of HgSO4/dil.H2SO4 with alkyne gives addition of water as per markonikoff's rule.

CH≡CH →H2OHgSO4,H2SO4 CH3CHO

Hence, by this process preparation of CH3CH2CHO
Cann't possible.

Hence CH3-CH2-CHO cannot be formed.

Topic: Chemistry, Aldehydes and Ketones, JEE Main, JEE Main 2021 (24 Feb Shift 2)
Which one of the following categories of animals, is correctly described with no single exception in it?

Options:
A All reptiles possess scales, have a threechambered heart and are cold-blooded (poikilothermal)
B All bony fishes have four pairs of gills and an operculum on each side
C All sponges are marine and have collared cells
D All mammals are viviparous and possess diaphragm for breathing

The correct answer is:
All bony fishes have four pairs of gills and an operculum on each side

Solution:
Prototherian mammals are oviparous. Sponges are aquatic mostly marine some freshwater have cellular grade of organization. Choanocytes or collar cells are characteristics of porifers. Four pairs of gills occur in bony fishes. The gills are covered over by operculum on either side.
All reptiles posses scales, are cold blood but have three-chambered and four-chambered heart.

Topic: Biology, Animal Kingdom, NEET, NEET 2012 (Mains)
Which one of the following categories of organism does not evolve oxygen during photosynthesis?

Options:
A Red algae
B Photosynthetic bacteria
C C4 plants with Kranz anatomy
D Blue green algae

The correct answer is:
Photosynthetic bacteria

Solution:
Organisms in the domain Bacteria perform non-oxygenic photosynthesis referred to as anoxygenic phototrophic bacteria. The first anoxygenic phototrophic bacterium was identified in 1901 and was subsequently described as Rhodospirillum species. Rhodospirillum species are purple bacteria that belong to the phylum Proteobacteria, and the term "purple bacteria", which refers to a major group among anoxygenic phototrophic bacteria. None of the anoxygenic phototrophic bacteria have the ability to use water as an electron donor (or cannot oxidize water), and, thus, perform photosynthesis using sulfide, hydrogen or organic substrates. Therefore, photosynthesis by these bacteria does not involve oxygen.

Topic: Biology, Photosynthesis in Higher Plants, NEET
Which one of the following cellular parts is correctly described?

Options:
A Thylakoids-Flattened membranous sacs forming the grana of chloroplasts
B Centrioles-Sites for active RNA synthesis
C Ribosomes-Those on chloroplasts are larger $(80 \mathrm{~S})$ while those in the cytoplasm are smaller (70 S)
D Lysosomes-Optimally active at a pH of about 8.5

The correct answer is:
Thylakoids-Flattened membranous sacs forming the grana of chloroplasts

Solution:
Centrioles are a membranous hollow microcylinders occur in pair and play important role in cell division.
Ribosomes in chloroplast are $70 \mathrm{~S}$ type while those of cytoplasm in eukaryotic cells are $80 \mathrm{~S}$ type. The enzymes of lysosome (called suicidal bag) function at acidic $\mathrm{pH}$ (i.e., 5).

Topic: Biology, Cell - The Unit of Life, NEET, NEET 2012 (Mains)
Which one of the following characteristics is common both in humans and adult frogs?

Options:
A Four chambered heart
B Internal fertilization
C Nucleated RBCs
D Ureotelic mode of excretion

The correct answer is:
Ureotelic mode of excretion

Solution:
Most animals convert toxic ammonia into less toxic urea and excreted it, e.g., adult frog and man.
Four-chambered heart is present in human but two-chambered in frog.
Nucleated RBCs are found in frog but not in human.
Fertilization is internal in human but external in frog.

Topic: Biology, Excretory Products and their Elimination, NEET, NEET 2012 (Mains)
Which one of the following characteristics is not correct for physical adsorption?

Options:
A
Adsorption increases with incresae in temperature

B
Adsorption is spontaneous

C
Both enthalpy and entropy of adsorption are negative

D
Adsorption on solids is reversible

The correct answer is:
Adsorption increases with incresae in temperature

Solution:
As adsorption is an exothermic process.
$\therefore$ Rise in temperature will decrease adsorption.

Topic: Chemistry, Surface Chemistry, JEE Main, JEE Main 2003
Which one of the following chemical agent is not being used for dry-cleaning of clothes?

Options:
A H2O2
B CCl4
C Liquid CO2
D Cl2C=CCl2

The correct answer is:
H2O2

Solution:
CO2,CCl4 and Cl2C=CCl2 are used as dry cleaning agents for clothes.

H2O2 is used as bleaching agent in laundry.

Topic: Chemistry, Environmental Chemistry, JEE Main, JEE Main 2021 (25 Jul Shift 1)
Which one of the following class of compounds is obtained by polymerization of acetylene ?

Options:
A Poly-ene
B Poly-amide
C Poly-yne
D Poly-ester

The correct answer is:
Poly-yne

Solution:
Acetylene is common the name of ethyne molecule. Polymerisation of alkynes produce addition polymers. Polymerisation of ethyne will produce poly-ethyne polymer. Polymers are large molecules formed by repeating units, which are known as monomers.

Topic: Chemistry, Polymers, JEE Main, JEE Main 2014 (09 Apr Online)
Which one of the following complexes in an outer orbital complex?

Options:
A
$\left[\mathrm{Fe}(\mathrm{CN})_6\right]^{4-}$

B
$\left[\mathrm{Ni}\left(\mathrm{NH}_3\right)_6\right]^{2+}$

C
$\left[\mathrm{Co}\left(\mathrm{NH}_3\right)_6\right]^{3+}$

D
$\left[\mathrm{Mn}(\mathrm{CN})_6\right]^{4-}$

The correct answer is:
$\left[\mathrm{Ni}\left(\mathrm{NH}_3\right)_6\right]^{2+}$

Solution:
No Solution Available

Topic: Chemistry, Coordination Compounds, JEE Main, JEE Main 2004
Which one of the following complexes is not expected to exhibit isomerism?

Options:
A $\left[\mathrm{Ni}\left(\mathrm{NH}_3\right)_4\left(\mathrm{H}_2 \mathrm{O}\right)_2\right]^{2+}$
B $\left[\mathrm{Pt}\left(\mathrm{NH}_3\right)_2 \mathrm{Cl}_2\right]$
C $\left[\mathrm{Ni}\left(\mathrm{NH}_3\right)_2 \mathrm{Cl}_2\right]$
D $\left[\mathrm{Ni}(\mathrm{en})_3\right]^{2+}$

The correct answer is:
$\left[\mathrm{Ni}\left(\mathrm{NH}_3\right)_2 \mathrm{Cl}_2\right]$

Solution:
$\left[\mathrm{Ni}\left(\mathrm{NH}_3\right)_2 \mathrm{Cl}_2\right]$ has tetrahedral geometry and thus, does not exhibit isomerism due to presence of symmetry elements.

Topic: Chemistry, Coordination Compounds, NEET, NEET 2010 (Mains)
Which one of the following complexes is violet in colour?

Options:
A Fe4Fe(CN)63·H2O
B Fe(CN)5NOS4-
C Fe(SCN)64-
D Fe(CN)64-

The correct answer is:
Fe(CN)5NOS4-

Solution:
Sulphur of organic compounds is detected by using sodium nitroprusside. With it sulphur forms a violet colour complex, called sodium thionitroprusside.

S2-+Na2Fe(CN)5(NO)+Sodium nitroprusside→Na4Fe(CN)5(NOS)Violet colour

Topic: Chemistry, Coordination Compounds, JEE Main, JEE Main 2021 (26 Aug Shift 1)
Which one of the following complexes shows optical isomerism?

Options:
A [CoNH3)3Br3
B [Co(NH3)4Br2]Br
C trans-[Co en) 2 Br 2 Br
D cis[Co(en)2Cl2]Cl
(en = ethylenediamine)

The correct answer is:
cis[Co(en)2Cl2]Cl
(en = ethylenediamine)

Solution:
Complex [Co(NH3)4Br2]Br have two G.I. which are optically inactive due to presence of plane of symmetry.
Complex [Co(NH3)3Br3] also have two optically inactive geometrical isomers due to presence of plane of symmetry.
complex trans-[Co en) 2 Br 2 Br is optically inactive.
Complex cis[Co(en)2Cl2]Cl is optically active due to formation of non-superimposable mirror image

Topic: Chemistry, Coordination Compounds, JEE Main
Which one of the following complexes shows optical isomerism? (en=ethylendiamine)

Options:
A transÂ Coen2Â Cl2Â Cl
B CoNH34 Cl2 Cl
C CoÂ NH33Â Cl3
D cis Coen2 Cl2Cl

The correct answer is:
cis Coen2 Cl2Cl

Solution:
[Co(NH3)3Cl3] shows two geometrical isomers and both can't show optical isomerism due to presence of plane of symmetry.
cis Coen2Cl2Cl shows optical isomerism
trans Coen2Cl2Cl forms identical mirror image due to presence of plane of symmetry.

[Co(NH3)4Cl2] shows geometrical isomerism.

Topic: Chemistry, Coordination Compounds, JEE Main, JEE Main 2016 (03 Apr)
Which one of the following complexes shows optical isomerism

Options:
A CoNH34Cl2Cl
B CoNH33Cl3
C cis[Coen)2Cl2Cl
D trans[Coen)2Cl2Cl
(en = ethylenediamine)

The correct answer is:
cis[Coen)2Cl2Cl

Solution:
Complex CoNH34Cl2Cl have two G.I. which are optically inactive due to presence of plane of symmetry.
Complex CoNH33Cl3 also have two optically inactive geometrical isomers due to presence of plane of symmetry.
Complex cis[Coen)2Cl2Cl is optically active due to formation of non-superimposable mirror image

trans[Coen)2Cl2Cl
Complex trans[Coen)2Cl2Cl is optically inactive.

Topic: Chemistry, Coordination Compounds, JEE Main
Which one of the following complexes will consume more equivalents of aqueous solution of AgNO3 ?

Options:
A Na2CrCl5H2O
B Na3CrCl6
C CrH2O5ClCl2
D CrH2O6Cl3

The correct answer is:
CrH2O6Cl3

Solution:
The number of ions will be precipitated only which are out of coordination sphere in given complexes.

[Cr(H2O)6]Cl3(aq)    ⇄   [Cr(H2O)6]3+(aq)  + 3Cl−(aq)
3Ag+  +  3Cl−  →3AgCl↓  (White)
More Equivalents of AgNO3 aqueous solution will be consumed by more Cl- ions given by the complex
Cl-aq+AgNO3→AgCl↓+NO3-aq

Topic: Chemistry, Coordination Compounds, JEE Main, JEE Main 2016 (09 Apr Online)
Which one of the following complexes will most likely absorb visible light?
(At nos. $\mathrm{Sc}=21, \mathrm{Ti}=22, \mathrm{~V}=23, \mathrm{Zn}=30$ )

Options:
A
$\left[\mathrm{Sc}\left(\mathrm{H}_2 \mathrm{O}\right)_6\right]^{3+}$

B
$\left[\mathrm{Ti}\left(\mathrm{NH}_3\right)_6\right]^{4+}$

C
$\left[\mathrm{V}\left(\mathrm{NH}_3\right)_6\right]^{3+}$

D
$\left[\mathrm{Zn}\left(\mathrm{NH}_3\right)_6\right]^{2+}$

The correct answer is:
$\left[\mathrm{V}\left(\mathrm{NH}_3\right)_6\right]^{3+}$

Solution:
The absorption of visible light and hence coloured nature of the transition metal cation is due to the promotion of one or more unpaired - $d$ - electron from a lower to higher level within same $d$-subshell. Hence higher will be the number of unpaired electron higher will be the absorpion in visible light.
The electronic configuration of the given elements is $\mathrm{Sc}^{3+}(18)=1 s^2 2 s^2 2 p^6 3 s^2 3 p^6 3 d^0 4 s^0-$ no unpaired $\mathrm{e}^{-}$.
$\mathrm{Ti}^{4+}(18)=1 s^2 2 \mathrm{~s}^2 2 p^6 3 s^2 3 p^6 3 d^0 4 s^0-$ no unpaired $\mathrm{e}^{-}$. $\mathrm{V}^{3+}(20)=1 s^2 2 s^2 2 p^6 3 s^2 3 p^6 3 d^2 4 s^0$ - Two unpaired $\mathrm{e}^{-}$. $\mathrm{Zn}^{2+}(28)=1 s^2 2 s^2 2 p^6 3 s^2 3 p^6 3 d^{10} 4 s^0-$ no unpaired $\mathrm{e}^{-}$. hence $\left[\mathrm{V}\left(\mathrm{NH}_3\right)_6\right]^{3+}$ will most likely absorb visible light.

Topic: Chemistry, Coordination Compounds, JEE Main
Which one of the following complexes will most likely absorb visible light?
(At nos. $\mathrm{Sc}=21, \mathrm{Ti}=22, \mathrm{~V}=23, \mathrm{Zn}=30$ )

Options:
A
$\left[\mathrm{Sc}\left(\mathrm{H}_2 \mathrm{O}\right)_6\right]^{3+}$

B
$\left[\mathrm{Ti}\left(\mathrm{NH}_3\right)_6\right]^{4+}$

C
$\left[\mathrm{V}\left(\mathrm{NH}_3\right)_6\right]^{3+}$

D
$\left[\mathrm{Zn}\left(\mathrm{NH}_3\right)_6\right]^{2+}$

The correct answer is:
$\left[\mathrm{V}\left(\mathrm{NH}_3\right)_6\right]^{3+}$

Solution:
The absorption of visible light and hence coloured nature of the transition metal cation is due to the promotion of one or more unpaired - $d$ - electron from a lower to higher level within same $d$-subshell. Hence higher will be the number of unpaired electron higher will be the absorpion in visible light.
The electronic configuration of the given elements is $\mathrm{Sc}^{3+}(18)=1 s^2 2 s^2 2 p^6 3 s^2 3 p^6 3 d^0 4 s^0-$ no unpaired $\mathrm{e}^{-}$.
$\mathrm{Ti}^{4+}(18)=1 s^2 2 \mathrm{~s}^2 2 p^6 3 s^2 3 p^6 3 d^0 4 s^0-$ no unpaired $\mathrm{e}^{-}$. $\mathrm{V}^{3+}(20)=1 s^2 2 s^2 2 p^6 3 s^2 3 p^6 3 d^2 4 s^0$ - Two unpaired $\mathrm{e}^{-}$. $\mathrm{Zn}^{2+}(28)=1 s^2 2 s^2 2 p^6 3 s^2 3 p^6 3 d^{10} 4 s^0-$ no unpaired $\mathrm{e}^{-}$. hence $\left[\mathrm{V}\left(\mathrm{NH}_3\right)_6\right]^{3+}$ will most likely absorb visible light.

Topic: Chemistry, Coordination Compounds, JEE Main, JEE Main 2014 (12 Apr Online)
Which one of the following complexes will most likely absorb visible light?
(Atomic numbers: Sc = 21, Ti = 22, V = 23, Zn = 30)

Options:
A [Sc(H2O)6]3+
B [V(NH3)6]3+
C [Ti(NH3)6]4+
D [Zn(NH3)6]2+

The correct answer is:
[V(NH3)6]3+

Solution:
The two electrons present in t2g orbitals can show d-d transitions between t2g and eg orbitals by absorbing visible light as CFSE is not very high due to weak NH3 ligand field in an octahedral geometry
2 1 Sc 3 + â 3 d â 2 2 Ti 4 + â 3 d â 3 0 Zn 2 + â 3 d 1 0 }
Configurations and d-d transitions leading to colouration etc, are not feasible.

Topic: Chemistry, Coordination Compounds, JEE Main
Which one of the following compounds contains β-C1-C4 glycosidic linkage ?

Options:
A Sucrose
B Amylose
C Lactose
D Maltose

The correct answer is:
Lactose

Solution:
Structure of Lactose C12H22O11

The linkage is between C-1 of β-Galactose and C-4 of β-Glucose.

Topic: Chemistry, Biomolecules, JEE Main
Which one of the following compounds contains β-C1-C4 glycosidic linkage ?

Options:
A Sucrose
B Amylose
C Lactose
D Maltose

The correct answer is:
Lactose

Solution:
Structure of Lactose C12H22O11

The linkage is between C-1 of β-Galactose and C-4 of β-Glucose.

Topic: Chemistry, Biomolecules, JEE Main, JEE Main 2021 (31 Aug Shift 1)
Which one of the following compounds has the smallest bond angle in its molecule?

Options:
A
$\mathrm{OH}_2$

B
$\mathrm{SH}_2$

C
$\mathrm{NH}_3$

D
$\mathrm{SO}_2$

The correct answer is:
$\mathrm{SH}_2$

Solution:
In $\mathrm{H}_2 \mathrm{~S}$, due to low electronegativity of sulphur the L.P. - L.P. repulsion is more than B.P. - B.P. repulsion and hence the bond angle is $92^{\circ}$.

Topic: Chemistry, Chemical Bonding and Molecular Structure, JEE Main, JEE Main 2003
Which one of the following compounds is an antifertility drug?

Options:
A
Aspirin

B
Chloromycetin

C
Saheli

D
Penicillin

The correct answer is:
Saheli

Solution:
The antifertility drugs are those chemical compounds which prevent pregnancy in woman. These, drugs controls the menstrual cycle and ovulation and so used as birth control drug or contraceptives.

Topic: Chemistry, Chemistry in Everyday Life, JEE Main, JEE Main 2012 (07 May Online)
Which one of the following compounds is inactive towards SN1 reaction?

Options:
A
B
C
D

The correct answer is:

Solution:
SN1 reaction mechanism follows a step-by-step process wherein first, the carbocation is formed from the removal of the leaving group. Then the carbocation is attacked by the nucleophile.

tertiary, benzylic or allylic carbocations are stable carbocations So, they can give this reaction.

But Bridge head carbocation formed in SN1pathway is unstable. So, option (C) does not give this reaction.

Topic: Chemistry, Haloalkanes and Haloarenes, JEE Main, JEE Main 2022 (28 Jun Shift 1)
Which one of the following compounds is non-aromatic?

Options:
A
B
C
D

The correct answer is:

Solution:
For the following ion/compounds

The main difference between aromatic antiaromatic and nonaromatic is that aromatic means having a delocalized pi electron system with (4n +2) electrons and antiaromatic means having a delocalized pi electron system with 4 electrons whereas nonaromatic means there is no delocalized electron system in that molecule.

Topic: Chemistry, General Organic Chemistry, JEE Main, JEE Main 2021 (24 Feb Shift 2)
Which one of the following compounds is not a yellow colored compound ?

Options:
A BaCrO4
B Zn2FeCN6
C K3CoNO26
D NH43[As Mo3O104]

The correct answer is:
Zn2FeCN6

Solution:
Colour of the compounds is due to transition of electrons.

Cyanides are not yellow.
BaCrO 4 - Yellow K 3 Co NO 2 6 - Yellow NH 4 3 As Mo 3 O 1 0 - Yellow
Zn2FeCN6 is bluish white.

Topic: Chemistry, d and f Block Elements, JEE Main, JEE Main 2015 (04 Apr)
Which one of the following compounds is not aromatic?

Options:
A
B
C
D

The correct answer is:

Solution:
It exists as non-planar tab-shaped so it is non aromatic.

Topic: Chemistry, General Organic Chemistry, JEE Main, JEE Main 2021 (26 Aug Shift 2)
Which one of the following compounds is used as a chemical in certain type of fire extinguishers

Options:
A Washing soda
B Baking soda
C Caustic soda
D Soda ash

The correct answer is:
Baking soda

Solution:
2NaHCO3(aq)+H2SO4(aq)→Na2SO4(aq)+2H2O(l)+2CO2(g)

When the fire extinguisher is operated by pressing the knob on it, the sulphuric acid gets mixed with sodium bicarbonate solution producing a lot of carbon dioxide gas. Carbon dioxide gas is neither combustible nor helps combustion.

Topic: Chemistry, s Block Elements, JEE Main, JEE Main 2022 (24 Jun Shift 2)
Which one of the following compounds of Group-14 elements is not known?

Options:
A GeCl62-
B SnOH62-
C SiCl62-
D SiF62-

The correct answer is:
SiCl62-

Solution:
SiCl62- does not exist due to steric crowding of surrounding atoms.

Topic: Chemistry, p Block Elements (Group 13 & 14), JEE Main, JEE Main 2021 (25 Jul Shift 1)
Which one of the following compounds on reduction with LiAIH4 yields a secondary amine?

Options:
A Methyl cyanide
B Nitroethane
C Methyl isocyanide
D Acetamide

The correct answer is:
Methyl isocyanide

Solution:
CH3-N≡C→LiAIH4 ReductionCH3-NH-CH3

Topic: Chemistry, Amines, JEE Main
Which one of the following compounds possesses the most acidic hydrogen?

Options:
A
B H3C-C≡C-H
C
D

The correct answer is:

Solution:

Topic: Chemistry, General Organic Chemistry, JEE Main, JEE Main 2020 (03 Sep Shift 1)
Which one of the following compounds show optical activity?

Options:
A
B
C
D

The correct answer is:

Solution:
It has two chiral carbons and the molecule has no plane of symmetry so it is optically active.
Rest all molecules have two chiral carbons atoms and the molecules have plane of symmetry also so they are optically inactive.

Topic: Chemistry, General Organic Chemistry, JEE Main
Which one of the following compounds when heated with $\mathrm{KOH}$ and a primary amine gives carbylamine test

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

The correct answer is:
$\mathrm{CHCl}_3$

Solution:
$\mathrm{CHCl}_3$ gives carbylamine test.
\(\underset{\substack{\text{Primary amine}} \\ (\mathrm{R}= \text{ alkyl or aryl)}}{\mathrm{R}-\mathrm{NH}_2+\mathrm{CHCl}_3+3 \mathrm{KOH(alc)}} \xrightarrow{(\text {warm})} \underset{\text{Alkyl isocyanide}}{\mathrm{R}-\mathrm{NC}+3 \mathrm{KCl}+3 \mathrm{H}_2 \mathrm{O}}\)

Topic: Chemistry, Amines, JEE Main
Which one of the following compounds will be most readily dehydrated?

Options:
A

B

C

D

The correct answer is:

Solution:
Dehydration of alcohols involve formation of carbocation intermediate. More the stability of carbocation, higher is the ease of dehydration. The order of stability of carbocation, given by the given compounds, is
Thus, compound given in OPTION (c) readily undergoes dehydration.

Topic: Chemistry, Alcohols Phenols and Ethers, NEET, NEET 2010 (Mains)