datavorous/entrance-exam-dataset huggingface dataset:
Which among the following reduces Fehling's solution?

Options:
A Acetic acid
B Formic acid
C Benzoic acid
D Salicylic acid

The correct answer is:
Formic acid

Solution:
Formic acid
has $-$ $\mathrm{CHO}$ group and therefore it reduces Fehling solution.

Topic: Chemistry, Aldehydes and Ketones, JEE Main
Which among the following salt solution in water shows $\mathrm{pH}$ less than 7 ?

Options:
A $\mathrm{CuCl}_2$
B $\mathrm{CH}_3 \mathrm{COONH}_4$
C $\mathrm{Na}_2 \mathrm{CO}_3$
D $\mathrm{KNO}_3$

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

Solution:
$\begin{aligned} & \mathrm{CuCl}_2 \rightarrow \text { Salt of } \mathrm{SA}+\mathrm{WB}\left(\text { Acidic } \mathrm{P}^{\mathrm{H}} < 7\right) \\ & \mathrm{CH}_3 \mathrm{COONH}_4 \rightarrow \text { Salt of WA }+\mathrm{WB}\left(\text { Neutral } \mathrm{P}^{\mathrm{H}}=7\right) \\ & \mathrm{Na}_2 \mathrm{CO}_3 \rightarrow \text { salt of WA }+\mathrm{SB}\left(\text { Basic } \mathrm{P}^{\mathrm{H}}>7\right) \\ & \mathrm{KNO}_3 \rightarrow \text { Salt of SA }+\mathrm{SB}\left(\text { Neutral } \mathrm{P}^{\mathrm{H}}=7\right)\end{aligned}$

Topic: Chemistry, Ionic Equilibrium, JEE Main
Which among the following species has unequal bond lengths?

Options:
A SiF4
B SF4
C XeF4
D BF4

The correct answer is:
SF4

Solution:
Species	Hybridisation	Bond length

BF4⊝	sp3 (Tetrahedral)	All bond lengths equal

XeF4	sp3d2 (sq. planar)	All bond lengths equal

SF4	sp3d (see - saw)	axial bond length > equitorial bond length

SiF4	sp3 (Tetrahedral)	all bond lengths equal

Topic: Chemistry, Chemical Bonding and Molecular Structure, JEE Main, JEE Main 2021 (25 Feb Shift 2)
Which among the following species have the same number of electrons in its outermost as well as penultimate shell

Options:
A Mg2+
B O2-
C F-
D Ca2+

The correct answer is:
Ca2+

Solution:
20Ca=2, 8, 8, 2
Ca2+= 2, 8, 8
Hence, Ca2+ has 8 electrons each in outermost and penultimate shell.

Topic: Chemistry, Classification of Elements and Periodicity in Properties, JEE Main
Which among the following statement is false

Options:
A The adsorption may be monolayered or multilayered
B Particle size of adsorbent will not affect the amount of adsorption
C Increase of pressure increases amount of adsorption
D Increase of temperature may decrease the amount of adsorption

The correct answer is:
Particle size of adsorbent will not affect the amount of adsorption

Solution:
Particle size of the adsorbent affects the amount of adsorption.
Smaller is the particle size of the adsorbent, higher is the amount of adsorption and vice versa.
Smaller particle size of the adsorbent corresponds to larger surface area.

Topic: Chemistry, Surface Chemistry, JEE Main
Which among the following statements about ozone depletion is NOT true?

Options:
A Depletion of ozone is most pronounced over Antarctica.
B Freons used in aerosol that enters into atmosphere causes depletion of ozone layer.
C Nitrogen oxide released from cars causes ozone depletion.
D Due to ozone depletion less amount of UV radiations reaches to earth surface.

The correct answer is:
Due to ozone depletion less amount of UV radiations reaches to earth surface.

Solution:
The ozone layer is mainly found in the lower portion of the earth's atmosphere. It has the potential to absorb around $97-99 \%$ of the harmful ultraviolet radiations coming from the sun that can damage life on earth. If the ozone layer was absent, millions of people would develop skin diseases and may have weakened immune systems.
Due to ozone depletion high amount of UV radiations reaches to earth surface

Topic: Chemistry, Environmental Chemistry, MHT CET, MHT CET 2021 (21 Sep Shift 2)
Which among the following statements are true for glycine?

1. It exists in crsytalline form

2. It is optically active

3. It is soluble in water

4. It can form Zwitter ions

Options:
A 1, 2 and 3
B 1, 2 and 4
C 1, 3 and 4
D 2, 3 and 4

The correct answer is:
1, 3 and 4

Solution:
It is ionic, so it exists in cyrstalline form because it is ionic, so it is soluble in water. Because acidic and basic groups are present in the same molecule, so internal salt formation occurs to form dipolar ion H3N+-CH2COO- .

Topic: Chemistry, Biomolecules, JEE Main
Which among the following statements is correct regarding the dependence of voltage gain of an amplifier on the frequency of the signal?

Options:
A does not depend upon frequency of the signal
B increases with frequency of the signal
C decreases with frequency of the signal
D initially constant and then decreases with frequency of the signal

The correct answer is:
initially constant and then decreases with frequency of the signal

Solution:
The voltage gain of an amplifier is initially constant and then decreases with the frequency of the signal.

Topic: Physics, Semiconductors, JEE Main
Which among the following statements is NOT true about Frenkel defect?

Options:
A It occurs in ionic compounds with sizes of cations and anions almost equal.
B The density of solid crystal and its chemical properties remain unchanged as no ions are missing from the crystal lattice as a whole.
C The crystal as whole remains electrically neutral because equal number of cations and anions are present.
D The ions of ionic compound must have low co-ordination number.

The correct answer is:
It occurs in ionic compounds with sizes of cations and anions almost equal.

Solution:
It occurs in an ionic compound in which size of cation is smaller than anions.

Topic: Chemistry, Solid State, MHT CET, MHT CET 2022 (06 Aug Shift 2)
Which among the following statements is true about Schottky defect?

Options:
A In this defect cation an anion are lacking in stoichiometric proportion
B Formation of metal ally is example of this defect
C In this cation or anion moves from regular site to place between lattice site
D In this regular cation is replace by different cation

The correct answer is:
In this defect cation an anion are lacking in stoichiometric proportion

Solution:
In Schottky defect, cation and anion are lacking in stoichiometric proportion. It is basically a vacancy defect in ionic solids. In order to maintain electrical neutrality, the number of missing cations and anions are equal. This defect can easily be illustrated by the following figure.

Topic: Chemistry, Solid State, MHT CET, MHT CET 2019 (Shift 1)
Which among the following will be named as dibromidobis (ethylene diamine)chromium(III) bromide?

Options:
A
$\left[\mathrm{Cr}(\mathrm{en})_3\right] \mathrm{Br}_3$

B
$\left[\mathrm{Cr}(\mathrm{en})_2 \mathrm{Br}_2\right] \mathrm{Br}$

C
$\left[\mathrm{Cr}(\text { en }) \mathrm{Br}_4\right]^{-}$

D
$\left[\mathrm{Cr}(\mathrm{en}) \mathrm{Br}_2\right] \mathrm{Br}$

The correct answer is:
$\left[\mathrm{Cr}(\mathrm{en})_2 \mathrm{Br}_2\right] \mathrm{Br}$

Solution:
$\left[\mathrm{Cr}(\mathrm{en})_2 \mathrm{Br}_2\right] \mathrm{Br}$ - dibromido bis (ethylene diamine)chromium(III) bromide

Topic: Chemistry, Coordination Compounds, JEE Main, JEE Main 2012 (Offline)
Which among the given below is a natural biodegradable polymer?

Options:
A Nylon-2-Nylon-6
B Poly lactic acid polymer
C Cellulose
D Nylon-2 polymer

The correct answer is:
Cellulose

Solution:
Cellulose is the natural fibre and biodegradable polymer while Nylon-2-Nylon-6 and Poly lactic acid polymer is synthetic biodegradable. Nylon-2 polymer synthetic polymer which is not biodegradable.

Topic: Chemistry, Polymers, JEE Main
Which among these is not associated with aliphatic compounds?

Options:
A They contain $(4 n+2)$ pi electrons
B Contain straight chain compounds
C Contain branched chain compounds
D Has appropriate number of $\mathrm{H}$-atoms and functional groups

The correct answer is:
They contain $(4 n+2)$ pi electrons

Solution:
Explanation: The aromatic compounds $(4 n+2)$ pi electrons, which comes under the classification of cyclic compounds and hence they are not associated with aliphatic compounds.

Topic: Chemistry, General Organic Chemistry, JEE Main
Which amongst the following is not a pesticide?

Options:
A DDT
B Dieldrin
C Organophosphate
D Sodium Arsenite

The correct answer is:
Sodium Arsenite

Solution:
Dichlorodiphenyltrichloroethane (DDT) is an insecticide used in agriculture. Dieldrin a decades-old chlorocarbon insecticide that has long been banned from use in most of the world. It was introduced in 1948 by the now-defunct J. Organophosphates are a group of human-made chemicals that poison insects and mammals. Organophosphates are the most widely used insecticides today. They are used in agriculture, the home, gardens, and veterinary practice.

These days, the pesticide industry has shifted its attention to herbicides such as sodium chlorate (NaClO3), sodium arsenite (Na3AsO3 ) and many others.

Topic: Chemistry, Environmental Chemistry, JEE Main, JEE Main 2022 (28 Jun Shift 1)
Which amongst the following is the most stable carbocation

Options:
A

B

C $\stackrel{+}{\mathrm{C}} \mathrm{H}_3$
D $\mathrm{CH}_3 \stackrel{+}{\mathrm{C}} \mathrm{H}_3$

The correct answer is:

Solution:
Due to $(+l)$ effect of three methyl group $3^{\circ}$ carbocation is more stable.

Topic: Chemistry, General Organic Chemistry, JEE Main
Which amongst the following is the strongest acid?

Options:
A CHCN3
B CHI3
C CHBr3
D CHCl3

The correct answer is:
CHCN3

Solution:
Acidic character α stability of conjugate base (anion)
Stability of anion α-M and –I
- M>-I( dominance )
Electron withdrawing groups increase acidic strength. Among the given compounds, the electron withdrawing strength of substituents

In case of halogen -I>+M and -I order of halogen Cl>Br>I

Hence, CH CN3 will be most acidic

Topic: Chemistry, General Organic Chemistry, JEE Main, JEE Main 2019 (09 Jan Shift 1)
Which amongst the following molecules on polymerization produces neoprene?

Options:
A CH2=CCH3-CH=CH2
B CH2=CH-CH=CH2
C CH2=CCl-CH=CH2
D CH2=CH-C≡CH

The correct answer is:
CH2=CCl-CH=CH2

Solution:
Neoprene (also polychloroprene) is a family of synthetic rubbers that are produced by polymerization of chloroprene. Neoprene exhibits good chemical stability and maintains flexibility over a wide temperature range.

The structure of the chloroprene is CH2=CCl-CH=CH2

The formation of neoprene is as follows,

Topic: Chemistry, Polymers, NEET, NEET 2023 (All India)
Which amongst the following reaction of alkyl halides produces isonitrile as a major products?
(A) $\mathrm{R}-\mathrm{X}+\mathrm{HCN} \rightarrow$
(B) $\mathrm{R}-\mathrm{X}+\mathrm{AgCN} \rightarrow$
(C) $\mathrm{R}-\mathrm{X}+\mathrm{KCN} \rightarrow$
(D) $\mathrm{R}-\mathrm{X}+\mathrm{NaCN} \underset{\mathrm{H}_2 \mathrm{O}}{\mathrm{C}_2 \mathrm{H}_5 \mathrm{OH}}$
Choose the most appropriate answer from the options given below

Options:
A (B) only
B (A) and (B) only
C (D) only
D (C) and (D) only

The correct answer is:
(B) only

Solution:
$\mathrm{KCN}$ is predominately ionic and provides cyanide ions in solution. Although both carbon and introgen atoms are in a position to donate electron pairs, the attack takes place mainly through carbon atom and not through nitrogen atom since $\mathrm{C}-\mathrm{C}$ bond is more stable than $\mathrm{C}-\mathrm{N}$ bond. However, AgCN is mainly covalent in nature and nitrogen is free to donate electron pair forming isocyanide as the major product
$\mathrm{R}-\mathrm{X}+\mathrm{AgCN} \longrightarrow \mathrm{R}-\mathrm{NC}+\mathrm{AgX}$

Topic: Chemistry, Haloalkanes and Haloarenes, NEET, NEET 2023 (Manipur)
Which animal has become extinct from India?

Options:
A Snow Leopard
B Hippopotamus
C Wolf
D Cheetah

The correct answer is:
Cheetah

Solution:
The 'Cheetah' has become extinct from India. The endangered subspecies Acinonyx jubatus venaticus lives in Asia (Iran). In 1990, there were reports in the Times of India of a cheetah sighting in eastern India.There is a chance some cheetahs remain in India, though it is doubtful. There have also been reports of Asiatic cheetahs in the Balochistan Province to be unverified. The cheetah prefers to live in an open biotope, such as semi-desert, prairie, and thick brush.

Topic: Biology, Biodiversity and its Conservation, NEET
Which are not position isomers?

Options:
A
B
C
D

The correct answer is:

Solution:
They are functional isomers.

Topic: Chemistry, General Organic Chemistry, JEE Main
Which are the staggered forms of ethane

Options:
A 1 and 4
B 3 and 4
C 2 and 4
D 1 and 3

The correct answer is:
2 and 4

Solution:
$2^{\text {nd }}$ and $4^{\text {th }}$ forms of ethane are staggered.

Topic: Chemistry, General Organic Chemistry, JEE Main
Which are the starting materials for the preparation of?

Options:
A
B
C
D Any of the three

The correct answer is:

Solution:
(a) Nitration is difficult to be carried out, further the $-\mathrm{NO}_{2}$ group will go to $m$-position to the $>\mathrm{C}=\mathrm{O}$ group
(b) Nitrobenzene, being deactivated toward electrophilic substitution will not undergo Friedal Craft reaction.
(c) Benzene easily undergoes Friedal Craft reaction forming the required product.

Topic: Chemistry, Carboxylic Acid Derivatives, JEE Main
Which artificial sweetener contains chlorine?

Options:
A Sucralose
B Alitame
C Saccharin
D Aspartame

The correct answer is:
Sucralose

Solution:
Sucralose is an artificial sweetener. The majority of ingested sucralose is not broken down by the body, so it is no caloric. The structure of the Sucralose is
Alitame is an aspartic acid-containing dipeptide sweetener. The structure of Alitame is
Saccharin is an artificial sweetener with effectively no food energy which is about 400 times as sweet as sucrose or table sugar, but has a bitter or metallic aftertaste, especially at high concentrations. It is used to sweeten products such as drinks, candies, cookies, medicines, and toothpaste. The structure of the Saccharin is
Aspartame is an artificial, non-saccharide sweetener used as a sugar substitute in some foods and beverages. The structure of Aspartame is

Topic: Chemistry, Chemistry in Everyday Life, JEE Main, JEE Main 2015 (11 Apr Online)
Which base is present in RNA but not in DNA?

Options:
A
Uracil

B
Thymine

C
Guanine

D
Cytosine

The correct answer is:
Uracil

Solution:
No Solution Available

Topic: Chemistry, Biomolecules, JEE Main
Which base is present in RNA but not in DNA?

Options:
A
Uracil

B
Thymine

C
Guanine

D
Cytosine

The correct answer is:
Uracil

Solution:
No Solution Available

Topic: Chemistry, Biomolecules, JEE Main, JEE Main 2004
Which behaves both as a nucleophile and electrophile

Options:
A $\mathrm{CH}_3 \mathrm{NH}_2$
B $\mathrm{CH}_3 \mathrm{Cl}$
C $\mathrm{CH}_3 \mathrm{CN}$
D $\mathrm{CH}_3 \mathrm{OH}$

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

Solution:
$\mathrm{CH}_3 \mathrm{CN}$ behaves both as nucleophile and electrophile.

Topic: Chemistry, General Organic Chemistry, JEE Main
Which belongs to the actinides series

Options:
A $Ce$
B $Cf$
C $\mathrm{Ca}$
D $Cs$

The correct answer is:
$Cf$

Solution:
$\mathrm{Ce}$-lanthanide, $C s$-alkali metal, $\mathrm{Cf}$-actinide, $\mathrm{Ca}$-alkaline earth metal.

Topic: Chemistry, d and f Block Elements, JEE Main
Which branched chain isomer of the hydrocarbon with molecular mass $72 \mathrm{~u}$ gives only one isomer of mono substituted alky halide?

Options:
A
Tertiary butyl chloride

B
Neopentane

C
Isohexane

D
Neohexane

The correct answer is:
Neopentane

Solution:
Mol. wt $=72 ~u$

Topic: Chemistry, Haloalkanes and Haloarenes, JEE Main, JEE Main 2012 (Offline)
Which carbon atom of deoxyribose sugar in DNA does not contain -C||-OH bond?

Options:
A C5
B C3
C C2
D C1

The correct answer is:
C2

Solution:
C-2 carbon atom of deoxyribose sugar in DNA does not contain -C||-OH bond.

Topic: Chemistry, Biomolecules, JEE Main
Which carbonyl compound would react violently with water?

Options:
A Propan-2-one (acetone)
B Ethanoyl chloride ( Acetyl chloride)
C Ethanoic acid (Acetic acid)
D Ethanal (Acetaldehyde)

The correct answer is:
Ethanoyl chloride ( Acetyl chloride)

Solution:
Ethanoyl chloride (Acetyl chloride)
Ethanoyl chloride is the correct answer; acid chlorides generally react violently with water.

Topic: Chemistry, Alcohols Phenols and Ethers, JEE Main
Which cells are mainly responsible for humoral immunity?

Options:
A Monocytes
B NK cell
C T-cells
D B-cells

The correct answer is:
B-cells

Solution:
2 special types of lymphocytes in our blood mediate the primary and secondary immune responses :
A. T-lymphocytes- These help the B-cells to produce antibodies.
B. B-lymphocytes - Involved in the synthesis of proteins called antibodies.

Topic: Biology, Human Health and Diseases, NEET
Which cells are responsible for the phagocytosis of antigens and removal of cellular debris?

Options:
A T helper cells
B Plasma cells
C Fibroblast
D Macrophages

The correct answer is:
Macrophages

Solution:
The macrophage's main role is to phagocytize bacteria and damaged tissue, and they also debride damaged tissue by releasing proteases.

Topic: Biology, Human Health and Diseases, NEET
Which cells of the pancreas are responsible for releasing a hormone that increases the rate of glycogenolysis?

Options:
A α -cell
B β -cell
C γ -cell
D δ -cell

The correct answer is:
α -cell

Solution:
Glucagon:
It is a peptide hormone.
Glucagon acts mainly on the liver cells (hepatocytes).
It increases blood sugar (hyperglycemia) to maintain the normal blood glucose levels by:
A. Stimulating glycogenolysis.
B. Stimulating the process of gluconeogenesis.
C. Reducing cellular glucose uptake and utilisation.
All the above functions clearly indicate that the glucagon is a hyperglycemic hormone.

Topic: Biology, Chemical Coordination and Integration, NEET
Which chemical change among the following involves absorption of heat?

Options:
A CaO+H2O→CaOH2
B Nag→Na+g+e-
C H2SO4conc.+H2Oexcess→H2SO4aq
D Al3++6H2O→AlH2O63+

The correct answer is:
Nag→Na+g+e-

Solution:
Na→Na+ in gaseous state requires energy which is known as ionisation enthalpy.

Topic: Chemistry, Thermodynamics (C), JEE Main
Which colour of the light has the longest wavelength?

Options:
A red
B blue
C green
D violet

The correct answer is:
red

Solution:
Among the given lights, red coloured light has the longest wavelength.

As wavelength increases from V to R in VIBGYOR. So, red colour has the largest wavelength. It is reverse of frequency.Violet has the shortest wavelength.

Topic: Physics, Electromagnetic Waves, JEE Main
Which compound amongst the following is not an aromatic compound?

Options:
A

B

C

D

The correct answer is:

Solution:
German chemist and physicist Erich Hückel proposed a theory to help determine if a planar ring molecule would have aromatic properties. His rule states that if a cyclic, planar molecule has 4n+2 π electrons, it is considered aromatic. This rule would come to be known as Hückel's Rule

In the above molecule,There is an sp3 hybridized carbon in the ring.Hence, it is not involved in conjugation. As delocalization of π electrons is not there throughout the ring.It is not an aromatic species.

It does not follow Huckel's rule.

But in the other options the species given that is ,andare aromatic as they obey Huckel's rule

Topic: Chemistry, General Organic Chemistry, JEE Main
Which compound does not possess linear geometry

Options:
A $\mathrm{CH}_2=\mathrm{CH}_2$
B $\mathrm{HC} \equiv \mathrm{CH}$
C $\mathrm{BeCl}_2$
D $\mathrm{CO}_2$

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

Solution:
Alkene does not show linear structure but it has planar structure due to $s p^2$ -hybridisation

Topic: Chemistry, Chemical Bonding and Molecular Structure, JEE Main
Which compound does not show geometrical isomerism

Options:
A 2-butene
B 2-pentene
C 2,3-dibromo-2-butene
D 2-methyl propene

The correct answer is:
2-methyl propene

Solution:
2-methyl propene does not show geometrical isomerism.

Topic: Chemistry, General Organic Chemistry, JEE Main
Which compound is formed when $\mathrm{CH}_3 \mathrm{OH}$ reacts with $\mathrm{CH}_3-\mathrm{Mg}-X$

Options:
A Acetone
B Alcohol
C Methane
D Ethane

The correct answer is:
Methane

Solution:
$\mathrm{CH}_3-\mathrm{OH}+\mathrm{CH}_3 \mathrm{Mg}-\mathrm{X} \rightarrow \mathrm{CH}_4+\mathrm{CH}_3 \mathrm{O}-\mathrm{Mg}-\mathrm{X}$

Topic: Chemistry, Alcohols Phenols and Ethers, JEE Main
Which compound is formed when phenol is oxidised with potassium permanganate?

Options:
A Benzoquinone
B Phenylamine
C Benzaldehyde
D Phenol remains unchanged

The correct answer is:
Benzaldehyde

Solution:
Phenol is oxidised to benzaldehyde when treated with potassium permanganate.

Topic: Chemistry, Alcohols Phenols and Ethers, NEET
Which compound needs chloral in its synthesis

Options:
A D. D. T.
B Gammexane
C Chloroform
D Michler’s Ketone

The correct answer is:
D. D. T.

Solution:
DDT is formed by reaction of chloral with chloro benzene.

Topic: Chemistry, Haloalkanes and Haloarenes, JEE Main
Which compound polymerizes to neoprene?

Options:
A \( F_{2} C=C F_{2} \)
B \( C l_{2} C=C . C l_{2} \)
C \( \mathrm{CH}_{2}=\mathrm{C} . \mathrm{Cl}-\mathrm{CH}=\mathrm{CH}_{2} \)
D \( \mathrm{CH}_{2}=\mathrm{CHCl} \)

The correct answer is:
\( \mathrm{CH}_{2}=\mathrm{C} . \mathrm{Cl}-\mathrm{CH}=\mathrm{CH}_{2} \)

Solution:
The most important synthetic rubber is Neoprene which is produced by the polymerization of 2-chloro-1,3-butadiene.
In this illustration, the dashed lines represent repetition of the same base units, so both the products and reactants are polymers. The reaction proceeds with a mechanism similar to the Friedel-Crafts mechanism. Cross-linkage between the chlorine atom of one chain and the double bond of another contributes to the overall elasticity of neoprene. This cross-linkage occurs as the chains lie next to each other at random angles, and the attractions between double bonds prevent them from sliding back and forth.

Topic: Chemistry, Polymers, JEE Main
Which compound (s) out of the following is/are not aromatic?

(A)

(B)

(C)

(D)

Options:
A (B), (C) and (D)
B (C) and (D)
C (B)
D (A) and (C)

The correct answer is:
(B), (C) and (D)

Solution:
is aromatic; $(4 \times 0+2)=2 \pi e^{-}$ in conjugationis aromis aromatic; $(4 \times 0+2)=2 \pi e^{-}$ in conjugation
is non aromatic due to the presence of $s p^{3}$ carbon

Topic: Chemistry, General Organic Chemistry, JEE Main, JEE Main 2019 (11 Jan Shift 1)
Which compound would give 5-keto-2-methyl hexanal upon ozonolysis?

Options:
A
B
C
D

The correct answer is:

Solution:

Topic: Chemistry, Aldehydes and Ketones, JEE Main, JEE Main 2015 (04 Apr)
Which compounds exhibits maximum dipole moment among the following?

Options:
A
B
C
D

The correct answer is:

Solution:
-NO2 group has electron withdrawing nature
-NH2 group has electron releasing nature so in para positions âÎ¼1 and âÎ¼2 will simply add up to give the maximum value of resultant dipole moment of the molecule (Î¼=Î¼1+Î¼2) .

Topic: Chemistry, Chemical Bonding and Molecular Structure, JEE Main, JEE Main 2015 (11 Apr Online)
Which curve represents zero order reaction for A→ products?

Options:
A
B
C
D

The correct answer is:

Solution:
For zero order reaction:
A  =  A 0  − kt
y =  A 0  − kx
slope=−ve

Topic: Chemistry, Chemical Kinetics, JEE Main
Which decolourises the colour of acidic $\mathrm{KMnO}_4$

Options:
A $\mathrm{CH}_3 \mathrm{COOH}$
B $\mathrm{CH}_3 \mathrm{CH}_2 \mathrm{COOH}$
C $\mathrm{COOH} \cdot \mathrm{COOH}$
D $\mathrm{CH}_3 \mathrm{COOC}_2 \mathrm{H}_3$

The correct answer is:
$\mathrm{COOH} \cdot \mathrm{COOH}$

Solution:

Topic: Chemistry, Carboxylic Acid Derivatives, JEE Main
Which diode is primarily used in optocouplers to provide electrical isolation between circuits?

Options:
A Zener diode
B Photodiode
C Light Emitting Diode (LED)
D Varactor diode

The correct answer is:
Photodiode

Solution:
Optocouplers use LEDs and photodiodes to provide electrical isolation between circuits by transferring signals via light.

Topic: Physics, Semiconductors, JEE Main