datavorous/entrance-exam-dataset huggingface dataset:
The reaction by which Benzaldehyde can not be prepared

Options:
A +H2 in presence of Pd-BaSO4
B +CO+HCl in presence of anhydrous AlCl3
C
D +CrO2Cl2 in CS2 followed by H3O+

The correct answer is:

Solution:
As benzoic acid don't give Clemmenson's reduction.
Rest other options are correct for the preparation of benzaldehyde.

Topic: Chemistry, Aldehydes and Ketones, NEET
The reaction

Can be classified as:

Options:
A Williamson ether synthesis reaction
B Alcohol formation reaction
C Dehydration reaction
D Williamson alcohol synthesis reaction

The correct answer is:
Williamson ether synthesis reaction

Solution:

Topic: Chemistry, Alcohols Phenols and Ethers, NEET, NEET 2016 (Phase 1)
The reaction centre in PS II has an absorption maxima at

Options:
A 780 nm
B 680 nm
C 700 nm
D 660 nm

The correct answer is:
680 nm

Solution:
The pigments involved in photochemical reactions are organised into two discrete photochemical light harvesting complexes (LHC) within the Photosystem I (PS I) and Photosystem II (PS II).

In PS I, the reaction centre chlorophyll-a has an absorption peak at 700 nm, hence is called P700.

In PS II the reaction centre chlorophyll-a has an absorption maxima at 680 nm, and is called P680.

Topic: Biology, Photosynthesis in Higher Plants, NEET, NEET 2023 (All India)
The reaction, CO(g) + 3H₂(g) → CH₄(g) + H₂O(g) is at equilibrium at 1300 K in a 1L flask. It also contains 0.30 mol of CO, 0.10 mol of H₂, and 0.02 mol of H₂O and an unknown amount of CH₄ in the flask. Determine the concentration of CH₄ in the mixture. The equilibrium constant, Kc for the reaction at the given temperature is 3.90.

Options:
A 0.0585 mol/L
B 0.32 mol/L
C 0.16 mol/L
D 0.64 mol/L

The correct answer is:
0.0585 mol/L

Solution:
Correct Option is : (A)
0.0585 mol/L

Topic: Chemistry, Ionic Equilibrium, NEET
The reaction condition leading to the best yield of C 2 H 5 Cl are

Options:
A C 2 H 6 ( excess )+C l 2 ââ â UVââlight
B C 2 H 6 +C l 2 ( excess ) → room  temp. dark
C C 2 H 6 +C l 2    → UV  light
D C 2 H 6 +C l 2 ( excess )ââ â UVââlight

The correct answer is:
C 2 H 6 ( excess )+C l 2    → UV  light

Solution:
During chlorination of alkane, if excess of alkane is treated with Cl 2 ( g ) in presence of light or heat, chance of monoâchlorination predomtextnate.

C 2 H 6 ( excess )+C l 2 ââ â UVââlight CH 3 âC H 2 âClâ+HCl

Topic: Chemistry, Haloalkanes and Haloarenes, NEET
The reaction Cu 2+ aq +2 Cl â aq âCu s + Cl 2 g has Ecello=-1.03 V. This reaction

Options:
A Can be made to produce electricity in voltaic cell
B Can be made to occur in an electrolytic cell
C Can occur in acidic medium only
D Can occur in basic medium only

The correct answer is:
Can be made to occur in an electrolytic cell

Solution:
Cu2++2Cl-→Cu+Cl2;Ecello<0
Reactions which have Ecello<0 (non-spontaneous) can be made to occur in a electrolytic cell.

Topic: Chemistry, Electrochemistry, NEET
The reaction CuO(s) + H₂(g) → Cu(s) + H₂O(g) involves a redox reaction because:

Options:
A Oxygen gains electrons, and Hydrogen loses electrons.
B Copper gains electrons, and Hydrogen loses electrons.
C Oxygen loses electrons, and Hydrogen gains electrons.
D Copper loses electrons, and Hydrogen gains electrons.

The correct answer is:
Copper loses electrons, and Hydrogen gains electrons.

Solution:
Correct Option is : (D)
Copper loses electrons, and Hydrogen gains electrons.

Topic: Chemistry, Redox Reactions, NEET
The reaction Fe₂O₃(s) + 3CO(g) → 2Fe(s) + 3CO₂(g) involves a redox reaction because:

Options:
A Iron gains electrons, and Carbon loses electrons.
B Iron loses electrons, and Carbon gains electrons.
C Oxygen gains electrons, and Carbon loses electrons.
D Oxygen loses electrons, and Carbon gains electrons.

The correct answer is:
Iron loses electrons, and Carbon gains electrons.

Solution:
Correct Option is : (B)
Iron loses electrons, and Carbon gains electrons.

Topic: Chemistry, Redox Reactions, NEET
The reaction given below is known as

C2H5ONa+IC2H5→C2H5OC2H5+NaI

Options:
A Kolbe's synthesis
B Wurtz's synthesis
C Williamson's synthesis
D Grignard's synthesis

The correct answer is:
Williamson's synthesis

Solution:
C2H5ONa+IC2H5→C2H5OC2H5+NaI.
This reaction is known as Williamson's synthesis.

Topic: Chemistry, Alcohols Phenols and Ethers, NEET
The reaction in photosynthesis where ATP is produced using sunlight occurs in the:

Options:
A Stroma
B Thylakoid
C Mitochondrial matrix
D Cytoplasm

The correct answer is:
Thylakoid

Solution:
The light reaction occurs in the thylakoid membrane. It contains the photosystems which work as light-harvesting complexes. ATP is synthesized during both cyclic and non-cyclic photophosphorylation.

Topic: Biology, Photosynthesis in Higher Plants, NEET
The reaction

is called

Options:
A Carbylamine reaction
B Hofmann reaction
C Gabriel phthalimide synthesis
D Cope reaction

The correct answer is:
Gabriel phthalimide synthesis

Solution:
This reaction is called Gabriel phthalimide synthesis.
This method is most suitable for 1° amine, because 1° halides are most reactive in SN2 displacement reaction. Halides in SN2 displacements are reactive. 2° amines give poor yields, due to elimination.

Topic: Chemistry, Amines, NEET
The reaction

is called:

Options:
A Williamson synthesis
B Williamson continuous etherification process
C Etard reaction
D Gatterman-Koch reaction

The correct answer is:
Williamson synthesis

Solution:
It is called Williamson's synthesis for ether formation.

Given reaction is Williamson's synthesis process. It is
an important laboratory method for the preparation of symmetrical and unsymmetrical ethers. In this method, an alkyl halide (1° or 2°) is allowed to react with sodium alkoxide to get ether.

Topic: Chemistry, Alcohols Phenols and Ethers, NEET, NEET 2015 (Phase 1)
The reaction

is called

Options:
A Williamson continuous etherification process
B Gatterman – Koch reaction
C Etard reaction
D Williamson Synthesis

The correct answer is:
Williamson Synthesis

Solution:
Given reaction is Williamson continuous etherification process. It
an important laboratory method for the preparation of symmetrical and unsymmetrical ethers. In this method, an alkyl halide (1° or 2°) is allowed to react with sodium alkoxide to get ether.

Topic: Chemistry, Alcohols Phenols and Ethers, NEET
The reaction,

M 2+ aq +M s ⇌ 2M + aq

is an example of:

Options:
A Reduction
B Oxidation
C Comproportionation
D Disproportionation

The correct answer is:
Comproportionation

Solution:
The reaction, in which two or more species undergo reduction as well as oxidation to give a single species are called comproportionation reaction. This is reverse of disproportionation reaction.
M 2+ aq +M s â 2M + aq
Reduction M +2 + e − →M
M→ M + + e −

Topic: Chemistry, Redox Reactions, NEET
The reaction, N2O4(g)→2NO2(g) , is a first order reaction, which of the following best describes the variation of concentration of N2O4 with time?

Options:
A
B
C
D

The correct answer is:

Solution:
For first order reaction, the concentration of reactant decreases exponentially with passage of time.

Topic: Chemistry, Chemical Kinetics, NEET
The reaction occurs spontaneously if :

Options:
A $\mathrm{T} \Delta \mathrm{S} < \Delta \mathrm{H}$ and both $\Delta \mathrm{H}$ and $\Delta \mathrm{S}$ are $+\mathrm{ve}$
B $\mathrm{T} \Delta \mathrm{S}>\Delta \mathrm{H}$ and $\Delta \mathrm{H}$ is + ve and $\Delta \mathrm{S}$ is $-\mathrm{ve}$
C $\mathrm{T} \Delta \mathrm{S}>\Delta \mathrm{H}$ and both $\Delta \mathrm{H}$ and $\Delta \mathrm{S}$ are $+\mathrm{ve}$
D $\mathrm{T} \Delta \mathrm{S}=\Delta \mathrm{H}$ and both $\Delta \mathrm{H}$ and $\Delta \mathrm{S}$ are + ve

The correct answer is:
$\mathrm{T} \Delta \mathrm{S}>\Delta \mathrm{H}$ and both $\Delta \mathrm{H}$ and $\Delta \mathrm{S}$ are $+\mathrm{ve}$

Solution:
$\Delta \mathrm{G}=\Delta \mathrm{H}-\mathrm{T} \Delta \mathrm{S}$
$\Delta \mathrm{G}=-v e$ for spontaneous reaction
When $\Delta \mathrm{S}=+v e, \Delta \mathrm{H}=+v e$ and $\mathrm{T} \Delta \mathrm{S}$
$>\Delta \mathrm{H}$
$\Rightarrow \Delta \mathrm{G}=-v e$
$$
\text { Related Theory }
$$

Topic: Chemistry, Thermodynamics (C), NEET, NEET 2005
The reaction of aqueous KMnO4 with H2O2 in acidic conditions gives:

Options:
A Mn4+ and O2
B Mn2+ and O2
C Mn2+ and O3
D Mn4+ and MnO2

The correct answer is:
Mn2+ and O2

Solution:
3H2SO4+2KMnO4+5H2O2→5O2+2MnSO4+8H2O+K2SO4

Topic: Chemistry, d and f Block Elements, NEET, NEET 2014
The reaction of aqueous KMnO4 with H2O2 in acidic conditions gives

Options:
A Mn4+ and MnO2
B Mn2+ and O2
C Mn4+ and O2
D Mn2+ and O3

The correct answer is:
Mn2+ and O2

Solution:
KMnO4 is a strong oxidising agent & wll oxidise H2O2 to O2.
2KMnO4+3H2SO4+5H2O2→K2SO4+2MnSO4+8H2O+5O2

Topic: Chemistry, Redox Reactions, NEET
The reaction of benzoyl chloride with phenol in presence of NaOH is called

Options:
A Schotten-Baumann reaction
B Bouveault-Blank reduction
C Clemmensen reduction
D Stephen's reduction

The correct answer is:
Schotten-Baumann reaction

Solution:
The reaction of benzoyl chloride with phenol in presence of NaOH is called Schotten-Baumann reaction

Topic: Chemistry, Alcohols Phenols and Ethers, NEET
The reaction of Br 2 /P or  Cl 2 /P with carboxylic acid to form Î±-halogenated acid is called

Options:
A Hunsdicker reaction
B Hell-Vohlard-Zelinsky reaction
C Claisen reaction
D Kolbe's reaction

The correct answer is:
Hell-Vohlard-Zelinsky reaction

Solution:
Replacement of α -H be halogen occurs
CH3COOH→Cl2,PCH2ClCOOH→Cl2,PCHCl2COOH→Cl2,PCCl3COOH

Topic: Chemistry, Carboxylic Acid Derivatives, NEET
The reaction of C6H5CH=CHCH3 with HBr produces:

Options:
A
B
C
D

The correct answer is:

Solution:

Topic: Chemistry, Hydrocarbons, NEET, NEET 2015 (Phase 1)
The reaction of C6H5CH=CHCH3 with HBr produces

Options:
A
B C6H5CH2CH2CH2Br
C
D

The correct answer is:

Solution:
The reaction of C6H5CH=CHCH3 with HBr produces 1-bromo-1-phenyl-propane as follows
It is a case of markovnikov's addition reaction.

Topic: Chemistry, Haloalkanes and Haloarenes, NEET
the reaction of C6H5O-Na+ and CO2 at 6 atm 400 K, followed by addition of aq. acid is called

Options:
A Reimer-Tiemann reaction
B Kolbe reaction
C Wurtz reaction
D Cannizzaro reaction

The correct answer is:
Kolbe reaction

Solution:
the reaction of C6H5O-Na+ and CO2 at 6 atm 400 K, followed by addition of aq. acid is called Kolbe reaction

Topic: Chemistry, Carboxylic Acid Derivatives, NEET
The reaction of chlorine-water with propene gives

Options:
A ClCH2-CH(OH)CH3
B CH2(OH)CH(Cl)CH3
C ClCH2CH2CH2OH
D ClCH(OH)CH2CH3

The correct answer is:
ClCH2-CH(OH)CH3

Solution:
Addition of Cl2(aq) (or HO-Cl) occurs according to Markownikov's rule as follows:
Here +ve part of addendum goes to the carbon atom of double bond that has more hydrogens and the negative part and the negative part is added to the unsaturated carbon with less hydrogen.

Topic: Chemistry, Hydrocarbons, NEET
The reaction of CO + HCl in the presence of AlCl3 with benzene to form benzaldehyde is called

Options:
A Meerwein-Ponndorf-Verley reaction
B Cannizzaro reaction
C Gatterman-Koch reaction
D Bayer-Villeger reaction

The correct answer is:
Gatterman-Koch reaction

Solution:
The reaction of CO + HCl in the presence of AlCl3 with benzene to form benzaldehyde is called Gatterman-Koch reaction.

Topic: Chemistry, Aldehydes and Ketones, NEET
The reaction of concentrated sulphuric acid with carbohydrates C12H22O11 is an example of

Options:
A Dehydration
B Oxidation
C Reduction
D Sulphonation

The correct answer is:
Dehydration

Solution:
C12H22O11→ dehydrationConc. H2SO4 12CBlack+11H2O

This reaction is called dehydration reaction.

Topic: Chemistry, Biomolecules, NEET, NEET 2020 (Phase 2)
The reaction of cyanamide, NH2CN (s), with dioxygen was carried out in a bomb calorimeter, and ∆U was found to be –742.7 kJ mol–1at 298 K. What is the enthalpy change for the reaction at 298 K? NH2CN (g) + 3/2 O2(g) → N2(g) + CO2(g) + H2O(l)

Options:
A –743.9 kJ
B –786.4 kJ
C –645.8 kJ
D –697.2 kJ

The correct answer is:
–743.9 kJ

Solution:
Correct Option is : (A)
–743.9 kJ

Topic: Chemistry, Thermodynamics (C), NEET
The reaction of ethyl p-aminobenzoate with HNO2 and then with HBF4 yields a compound (X), a crystalline ionic compound. Compound (X) when heated forms C9H9O2F(Y) . The compound (Y) is

Options:
A ethyl p-fluorobenzoate
B ethyl o-fluorobenzoate
C ethyl m-fluorobenzoate
D mixture of all the above

The correct answer is:
ethyl p-fluorobenzoate

Solution:
This conversion occurs as follows to give ethyl p-fluorobenzoate

Topic: Chemistry, Amines, NEET
The reaction of H2O2 with H2S is an example of ......... reaction.

Options:
A addition
B oxidation
C reduction
D redox

The correct answer is:
redox

Solution:
It is an example of redox reaction
H2S+H2O2→2H2O+S
S 2− is oxdisied and O 2 2− is reduced.

Topic: Chemistry, Redox Reactions, NEET
The reaction of H3N3B3Cl3 (A) with LiBH4 in tetrahydrofuran gives inorganic benzene (B). Further, the reaction of (A) with (C) leads to H3N3B3(Me)3 . Compounds (B) and (C) respectively, are

Options:
A Borazine and MeBr
B Boron nitride and MeBr
C Diborane and MeMgBr
D Borazine and MeMgBr

The correct answer is:
Borazine and MeMgBr

Solution:
Here B is Borazine and C is MeMgBr. The reactions are as follows
B3N3H3Cl3A+LiBH4âB3N3H6BInorganicBenzeneor Borazine
B3N3H3Cl+MeMgBrCâB3N3H3CH33+3MgBrCl

Topic: Chemistry, p Block Elements (Group 13 & 14), NEET
The reaction of hydrogen and iodine monochloride is given as:
$\mathrm{H}_{2(g)}+2 \mathrm{ICl}_{(g)} \rightarrow 2 \mathrm{HCl}_{(g)}+\mathrm{I}_{2(g)}$
This reaction is of first order with respect to $\mathrm{H}_{2(g)}$ and $\mathrm{lCl}_{(g)+}$ following mechanisms were proposed
Mechanism A:
$\mathrm{H}_{2(g)}+2 \mathrm{ICl}_{(g)} \rightarrow 2 \mathrm{HCl}_{(g)}+\mathrm{H}_{2(g)}$
Mechanism B:
$\begin{aligned}
& \mathrm{H}_{2(g)}+\mathrm{ICl}_{(g)} \rightarrow \mathrm{HCl}_{(g)}+\mathrm{HI}_{(g)} \text { :slow } \\
& \mathrm{Hl}_{(g)}+\mathrm{lCl}_{(g)} \rightarrow \mathrm{HCl}_{(g)}+\mathrm{l}_{2(g)} \text {; fast }
\end{aligned}$
Which of the above mechanism(s) can be consistent with the given information about the reaction?

Options:
A A and B both
B neither A nor B
C A only
D B only

The correct answer is:
A and B both

Solution:
The slowest step is the rate determining step thus the mechanism $\mathrm{B}$ will be more consistent because it involve one molecule of $\mathrm{H}_2$ and one molecule of ICl. It can be expressed as
$r=k\left[\mathrm{H}_2\right][\mathrm{ICl}]$
Related Theory
The rate determining step in a reaction mechanism is characterised by high activation energy. Usually, the first step is the slow step since it has the highest activation energy.

Topic: Chemistry, Chemical Kinetics, NEET, NEET 2007
The reaction of RCN with R'MgX , followed by hydrloysis gives

Options:
A an aldehyde
B a ketone
C 2° alcohol
D 3° alcohol

The correct answer is:
a ketone

Solution:
The reaction of RCN with R'MgX , followed by hydrloysis gives a ketone as follows

Topic: Chemistry, Aldehydes and Ketones, NEET
The reaction of (S)-2-bromobutane with OH- to produce (R)-butan-2-ol will be

Options:
A first order in 2-bromobutane only
B first order in OH- only
C first order in 2-bromobutane and first order in OH-
D second order in OH-

The correct answer is:
first order in 2-bromobutane and first order in OH-

Solution:
Configuration invert, means S N 2 reaction takes place
Rate = K[Substrate] [OH-]

Topic: Chemistry, Haloalkanes and Haloarenes, NEET
The reaction of toluene with Cl2 inpresence of FeCl3 gives ‘X’ and reaction in presence of light gives ‘Y’. Thus, ‘X’ and ‘Y’ are

Options:
A X = Benzyl chloride, Y = m-chlorotoluene
B X = Benzyl chloride, Y = o-chlorotoluene
C X = m- chlorotoluene, Y = p-chlorotoluene
D X = o-chlorotoluene and p-chlorotoluene, Y = -trichloromethyl benzene

The correct answer is:
X = o-chlorotoluene and p-chlorotoluene, Y = -trichloromethyl benzene

Solution:

Topic: Chemistry, Hydrocarbons, NEET
The reaction of toluene with $\mathrm{Cl}_2$ in presence of $\mathrm{FeCl}_3$ gives ' $X$ ' and reaction in presence of light gives ' $Y$ '. Thus, ' $X$ ' and ' $Y$ ' are

Options:
A $\mathrm{X}=$ Benzal chloride, $\mathrm{Y}=\mathrm{o}$-chlorotoluene
B $\mathrm{X}=m$-chlorotoluene, $\mathrm{Y}=\mathrm{p}$-chlorotoluene
C $\mathrm{X}=a$-and $p$-chlorotoluene
$\mathrm{Y}=$ trichloromethyl benzene
D $\mathrm{X}=$ benzyl chloride, $\mathrm{Y}=$ m-chlorotoluene

The correct answer is:
$\mathrm{X}=a$-and $p$-chlorotoluene
$\mathrm{Y}=$ trichloromethyl benzene

Solution:
Key Idea In the presence of halogen carrier, electrophilic substitution accurs while in the presence of sunlight, substitution accurs at the side chain.

Topic: Chemistry, Haloalkanes and Haloarenes, NEET, NEET 2010 (Screening)
The reaction of white phosphorus with aqueous NaOH gives phosphine along with another phosphorus containing compound. The oxidation states of phosphorus in phosphine and the other product are respectively

Options:
A Redox reaction; - 3 and - 5
B Redox reaction; + 3 and + 5
C Disproportionation reaction; - 3 and + 1
D Disproportionation reaction; - 3 and + 3

The correct answer is:
Disproportionation reaction; - 3 and + 1

Solution:
The balanced disproportionation reaction involving white phosphorus with aqueous NaOH is
at low concentration of NaOH

Topic: Chemistry, p Block Elements (Group 15, 16, 17 & 18), NEET
The reaction of white phosphorus with aqueous NaOH gives phosphine along with another phosphorus containing compound. The reaction type; the oxidation state of phosphorus in phosphine and the other product are respectively

Options:
A Redox reaction; +3 and +5
B Redox reaction; -3 and – 5
C Disproportionation reaction; - 3 and +3
D Disproportionation reaction; - 3 and +1

The correct answer is:
Disproportionation reaction; - 3 and +3

Solution:
The reaction of white phosphorus with aqueous NaOH gives phosphine along with sodium hydrogen phosphite. It is Disproportionation reaction in which oxidation number of phosphorus is changing from 0 to -3 and +3 as follows
P 4 0 +NaOH aq → PH 3 −3 + Na 2 HPO 3 +3

Topic: Chemistry, p Block Elements (Group 15, 16, 17 & 18), NEET
The reaction quotient $(\mathrm{Q})$ for the reaction:
$\mathrm{N}_{2(g)}+3 \mathrm{H}_{2(g)} \rightleftharpoons 2 \mathrm{NH}_{3(\mathrm{~g})}$
is given by $\mathrm{Q}=\frac{\left[\mathrm{NH}_3\right]^2}{\left[\mathrm{~N}_2\right]\left[\mathrm{H}_2\right]^3}$ The reaction will proceed from right to left if:

Options:
A $\mathrm{Q}=\mathrm{K}_e$
B $\mathrm{Q} < \mathrm{K}_c$
C $\mathrm{Q}>\mathrm{K}_c$
D $Q=0$

The correct answer is:
$\mathrm{Q}>\mathrm{K}_c$

Solution:
$\mathrm{N}_{2(g)}+3 \mathrm{H}_{2(g)} \rightleftharpoons 2 \mathrm{NH}_{3(g)}$
$\begin{aligned}
& \mathrm{K}_{\mathrm{C}}=\frac{\left[\mathrm{NH}_3\right]^2}{\left[\mathrm{~N}_2\right]\left[\mathrm{H}_2\right]^3}: \\
& \Delta n=2-4=-2
\end{aligned}$
Thus, the reaction moves in forward direction, when $\mathrm{Q} > \mathrm{K}_c$.

Topic: Chemistry, Chemical Equilibrium, NEET, NEET 2003
The reaction, RNH2+CHCl3+3KOHEthanolicâR-N+â¡C- +3KCl+3H2O is called

Options:
A Cope reaction
B Curtius reaction
C Hoffmann-bromamide reaction
D Carbylamine reaction

The correct answer is:
Carbylamine reaction

Solution:
The reaction, RNH2+CHCl3+3KOHEthanolicâR-N+â¡C- +3KCl+3H2O is called Carbylamine reaction
Mechanism CHCl 3 +KOH→ CCl 2 (Electrophilic carbene) +  H 2 O + KCl
R-N. .H2+:CCl2âR-+N | | H H-C||:-Cl Cl â2KOH-2HClR-N+â¡C-

Topic: Chemistry, Amines, NEET
The reaction, water gas CO +  H 2  +  H 2 at 673K, 300 atmosphere in presence of the catalyst Cr 2 O 3 /ZnO is used for the manufacture of

Options:
A HCHO
B HCOOH
C CH 3 OH
D CH 3 COOH

The correct answer is:
CH 3 OH

Solution:
COââ+â H 2 ï¸¸ waterâgas +â H 2 â 672 K, 200 atm Cr 2 O 3 /ZnO CH 3 OH

Topic: Chemistry, Alcohols Phenols and Ethers, NEET
The reaction with incorrect major product is –

Options:
A HC≡CH→47%H2SO4CH3CHO
B Me2CHCl→Ag2OMe2CHOH
C C6H5OH+CH2N2→BF3C6H5OCH3
D CH3CBr2CBr2CH3+2Zn→EtOHCH3C≡CCH3

The correct answer is:
Me2CHCl→Ag2OMe2CHOH

Solution:
Alkyl halide with Ag2O gives ether and with moist Ag2O give an alcohol, Me2CH-Cl→Ag2O Me2CH-O-CHMe2

Topic: Chemistry, Alcohols Phenols and Ethers, NEET
The reaction X→ product follows first order kinetics. In 40 minutes, the concentration of X changes from 0.1 M to 0.025 M, then the rate of reaction when concentration of X is 0.01 M is

Options:
A 3.47×10-5 M/min
B 1.73×10-4 M/min
C 1.73×10-5 M/min
D 3.47×10-4 M/min

The correct answer is:
3.47×10-4 M/min

Solution:
k= 2.303 t log C 0 C t = 2.303 40 log 0.1 0.025
=2.30340log4=2.303×0.602140 min-1
Rate=kA=2.303×0.602140min-1×0.01 M
=3.47×10-4 M/min

Topic: Chemistry, Chemical Kinetics, NEET
The reactions that occurs at the cathode of a common dry cell is

Options:
A 2ZnO2+Mn2++2e-→MnZn2O4
B Mn→Mn2++2e-
C 2MnO2+Zn2++2e-→ZnMn2O4
D Zn→Zn2++2e-

The correct answer is:
2MnO2+Zn2++2e-→ZnMn2O4

Solution:
In common dry cell.
Anode: Zn→Zn+++2e-
Cathode: 2MnO2+Zn+++2e-→ZnMn2O4 .

Topic: Chemistry, Electrochemistry, NEET
The reactivity of transition elements decreases almost regularly from Sc to Cu. Explain.

Options:
A The atomic sizes of transition metals increase from Sc to Cu.
B The effective nuclear charge experienced by electrons increases from Sc to Cu.
C The ionization energies of transition metals increase from Sc to Cu.
D The electron affinity of transition metals increases from Sc to Cu.

The correct answer is:
The ionization energies of transition metals increase from Sc to Cu.

Solution:
Correct Option is : (C)
The ionization energies of transition metals increase from Sc to Cu.

Topic: Chemistry, d and f Block Elements, NEET
The reading of ammeter in the circuit shown is

Options:
A 6 A
B 4 A
C 2 A
D 1 A

The correct answer is:
4 A

Solution:
Redraw the circuit as follows:
∴I=61.5=4 A

Topic: Physics, Current Electricity, NEET
The reading of an ideal voltmeter in the circuit shown is

Options:
A $0.6 \mathrm{~V}$
B $0 \mathrm{~V}$
C $0.5 \mathrm{~V}$
D $0.4 \mathrm{~V}$

The correct answer is:
$0.4 \mathrm{~V}$

Solution:
The given circuit diagram can be drawn as shown below
The equivalent resistance of circuit is given by
$$
\begin{aligned}
& \frac{\mathrm{l}}{\mathrm{R}_{\mathrm{eq}}}=\frac{\mathrm{l}}{\mathrm{R}_{\mathrm{AE}}}+\frac{\mathrm{l}}{\mathrm{R}_{\mathrm{DF}}} \\
& =\frac{1}{(20+30)}+\frac{1}{(30+20)} \\
& =\frac{1}{50}+\frac{1}{50}=\frac{2}{50} \\
& \Rightarrow \quad \mathrm{R}_{\mathrm{eq}}=25 \Omega \\
&
\end{aligned}
$$
As the resistance of two branches is same i.e. $50 \Omega$.
So, the current $\mathrm{I}_1=\mathrm{I}_2$
$$
\Rightarrow \quad \begin{aligned}
\mathrm{I} & =\mathrm{I}_1+\mathrm{I}_2 \\
\frac{2}{25} & =2 \mathrm{I}_1 \Rightarrow \mathrm{I}_2=\mathrm{I}_1=\frac{1}{25} \mathrm{~A}
\end{aligned}
$$
$\therefore$ The voltage across $\mathrm{AB}$
$$
\mathrm{V}_1=\mathrm{I}_1 \mathrm{R}_1=\frac{1}{25} \times 20
$$
and voltage across $C D$
$$
\begin{aligned}
\mathrm{V}_2= & \mathrm{I}_2 \mathrm{R}_2=\frac{1}{25} \times 30 \\
\therefore \text { Voltmeter reading } & =\mathrm{V}_2-\mathrm{V}_1 \\
& =\frac{30}{25}-\frac{20}{25} \\
& =\frac{10}{25}=0.4 \mathrm{~V}
\end{aligned}
$$

Topic: Physics, Current Electricity, NEET, NEET 2019 (Odisha)
The reading of brass scale at room temperature is L1 . Above room temperature reading is L2 and below room temperature reading is L3. Then, relation between the readings is

Options:
A L1>L2>L3
B L3>L1>L2
C L2>L3>L1
D L1=L2=L3

The correct answer is:
L3>L1>L2

Solution:
On increasing the temperature, scale expands. So it reads less and on cooling it contracts so it reads more.
Therefore L3>L1>L2

Topic: Physics, Thermal Properties of Matter, NEET
The reading of the ammeter and voltmeter are (Both the instruments are ac meters and measures rms value) -

Options:
A 2 A, 110 V
B 2 A, 0 V
C 2 A, 55 V
D 1 A, 0 V

The correct answer is:
2 A, 0 V

Solution:
The circuit is RLC resonant circuit.
∴ Reading of voltmeter=VL-VC=0
Reading of ammeter=ErmsZ=ErmsR=11055=2 A

Topic: Physics, Alternating Current, NEET