List of top Chemistry Questions asked in JEE Main

Isomeric amines with molecular formula C₈ H₁₁N give the following tests
Isomer (P) ⇒ Can be prepared by Gabriel phthalimide synthesis
Isomer (Q) ⇒ Reacts with Hinsberg’s reagent to give solid insoluble in NaOH
Isomer (R) ⇒ Reacts with HONO followed by β-naphthol in NaOH to give red dye.
Isomers (P), (Q) and (R) respectively are

List-I	Industry	List-II	Waste Generated
(A)	Steel Plants	(I)	Gypsum
(B)	Thermal Power Plants	(II)	Fly ash
(C)	Fertilizer industries	(III)	Slag
(D)	Ppaer mills	(IV)	Bio-degradable Wastes

Choose the correct answer from the options given below:

Which of the following statements are correct?
(A) The M³⁺/M²⁺ reduction potential for iron is greater than manganese
(B) The higher oxidation states of first row dblock elements get stabilized by oxide ion.
(C) Aqueous solution of Cr²⁺ can liberate hydrogen from dilute acid.
(D) Magnetic moment of V²⁺ is observed between 4.4-5.2 BM Choose the correct answer from the options given below:

Given below are two reactions, involved in the commercial production of dihydrogen (H₂). The two reactions are carried out at temperature “T₁ ” and “T₂ ” respectively
$C(S)+H_2O(g)\underrightarrow {T_1}\;CO(g)+H_2(g)$
$CO(g)+H_2O(g)\underrightarrow{T_2}\;CO_2(g)+H_2(g)$
The temperature $T_1$ and $T_2$ are correctly related as

Number of molecules and moles in 2.8375 litre of O₂ at STP.

At what $pH$, given half cell $MnO _4^{-}(01 M ) \mid Mn ^{2+}(0001 M )$ will have electrode potential of $1.282\, V$? (Nearest Integer)
(Given: $E _{ MnO _{4}^-| Mn ^{2+}}^{ o }=154 \,V , \frac{2303 RT }{ F }=0059\, V$)

(i) $X ( g ) \rightleftharpoons Y ( g )+ Z$ (g) $K _{ p 1}=3$
(ii)$A ( g ) \rightleftharpoons 2 B ( g )\,\, K _{ p 2}=1$
If the degree of dissociation and initial concentration of both the reactants $X ( g )$ and $A ( g )$ are equal, then the ratio of the total pressure at equilibrium $\left(\frac{p_1}{p_2}\right)$ is equal to $x : 1$. The value of $x$ is _________ (Nearest integer)

The total number of chiral compound/s from the following is ________

At $25^{\circ} C$, the enthalpy of the following processes are given:
$H _2( g )+ O _2( g ) \rightarrow 2 OH ( g ) \Delta H ^{\circ} =78 \,kJ \,mol ^{-1}$
$H _2( g )+1 / 2 O _2( g ) \rightarrow H _2 O ( g ) \Delta H ^{\circ} =-242 \,kJ \,mol ^{-1}$
$H _2( g ) \rightarrow 2 H ( g ) \Delta H ^{\circ} =436\, kJ \,mol ^{-1}$
$1 / 2 O _2( g ) \rightarrow O ( g ) \Delta H ^{\circ} =249\, kJ\, mol ^{-1}$
What would be the value of $X$ for the following reaction?______ (Nearest integer)
$H _2 O ( g ) \rightarrow H ( g )+ OH ( g ) \Delta H ^{\circ}= X\, kJ\, mol -1$

$25 \,mL$ of an aqueous solution of $KCl$ was found to require $20\, mL$ of $1\, M$ $AgNO _3$ solution when titrated using $K _2 CrO _4$ as an indicator What is the depression in freezing point of $KCl$ solution of the given concentration? _________ (Nearest integer) (Given: $K _f=20 \,K \,kg \,mol ^{-1}$)
Assume 1) $100 \%$ ionization and
2) density of the aqueous solution as $1 \,g \,mL ^{-1}$

Number of isomeric compounds with molecular formula $C _9 H _{10} O$ which
(i) do not dissolve in $NaOH$
(ii) do not dissolve in $HCl$
(iii) do not give orange precipitate with 2,4-DNP
(iv) on hydrogenation give identical compound with molecular formula $C _9 H _{12} O$ is _________

$A$ and $B$ are two substances undergoing radioactive decay in a container The half life of $A$ is $15 min$ and that of $B$ is $5\, min$ If the initial concentration of $B$ is $4$ times that of $A$ and they both start decaying at the same time, how much time will it take for the concentration of both of them to be same? ______ min

The density of $3 M$ solution of $NaCl$ is $10 \,g \,mL -1$. Molality of the solution is _______ $\times 10^{-2} m$ (Nearest integer). Given: Molar mass of Na and $Cl$ is $23$ and $355 \,g \,mol ^{-1}$ respectively.

Identify the incorrect option from the following:

Match List I with List II

List I		List II
A	Tranquilizers	i	Anti blood clotting
B	Aspirin	ii	Salvarsan
C	Antibiotic	iii	Antidepressant drugs
D	Antiseptic	iv	Soframicine

Choose the correct answer from the options given below:

The correct representation in six-membered pyranose form for the following sugar $ [X]$ is

But-2-yne is reacted separately with one mole of Hydrogen as shown below:

A. A is more soluble than B
B. B The boiling point & melting point of $A$ are higher and lower than $B$ respectively
C. A is more polar than $B$ because dipole moment of $A$ is zero
D. $Br _2$ adds easily to $B$ than $A$
Identify the incorrect statements from the options given below:

4.5 moles each of hydrogen and iodine is heated in a sealed ten litre vessel. At equilibrium, 3 moles of HI were found. The equilibrium constant for H₂(g) + I₂(g) ⇋ 2HI(g) is _____________ .

The number of possible isomeric products formed when 3-chioro-1-butene reacts with HCl through carbocation formation is __________

The volume of hydrogen liberated at STP by treating 2.4 g of magnesium with excess of hydrochloric acid is _________ × 10^–2 L
Given : Molar volume of gas is 22.4 L at STP.
Molar mass of magnesium is 24 g mol^–1

The number of correct statement from the following is _________ .
A. For 1s orbital, the probability density is maximum at the nucleus
B. For 2s orbital, the probability density first increases to maximum and then decreases sharply to zero.
C. Boundary surface diagram of the orbitals encloses a region of 100% probability of finding the electron.
D. p and d-orbitals have 1 and 2 angular nodes respectively E. probability density of p-orbital is zero at the nucleus