List of top Questions asked in JEE Main

In \(3d\) series, the metal having the highest \(M^{2+}/M\) standard electrode potential is
If the area of the region \(\{(x, y) : x^{2/3} + y^{2/3} \leq 1, x + y \geq 0, y \geq 0\}\) is A, then \(\frac{(256 A)}{\pi} \)is equal to_______.
Arrange the following coordination compounds in the increasing order of magnetic moments. (Atomic numbers: \(Mn = 25; Fe = 26\))
(1) \([FeF_6]^{3–}\)
(2) \([Fe(CN)_6]^{3–}\)
(3) \([MnCl_6]^{3–}\) (high spin)
(4) \([Mn(CN)_6]^{3–}\)
Let \(y = y(x)\) be the solution of the differential equation \((1 - x^2) \, dy = (xy + (x^3 + 2) \sqrt{1 - x^2}) \, dx \quad -1 < x < 1\), and \(y(0) = 0.\) If \(\int_{-\frac{1}{2}}^{\frac{1}{2}} \sqrt{1 - x^2} \, y(x) \, dx = k\) then \(k^{−1}\) is equal to_______.
On the surface of polar stratospheric clouds, hydrolysis of chlorine nitrate gives A and B while its reaction with HCl produces B and C. A, B and C are, respectively
Let a circle C of radius 5 lie below the x-axis. The line L1 : 4x + 3y + 2 = 0 passes through the centre P of the circle C and intersects the line L2 : 3x – 4y – 11 = 0 at Q. The line L2 touches C at the point Q. Then the distance of P from the line 5x – 12y + 51 = 0 is _____
Which of the following is most stable?
What will be the major product of the following sequence of reactions?
\(n−Bu−≡ \xrightarrow[{(ii)Lindlar catalyst, H_2}]{(i)n-BuLi,n-C_5H_{11}Cl}\)
Let S = {E1, E2, ……………., E8} be a sample space of a random experiment such that \(P(E_n) = \frac{n}{36}\) for every n = 1, 2, ………, 8. Then the number of elements in the set\(\{ A \subseteq S : P(A) \geq \frac{4}{5} \}\) is_________.
For complete combustion of methanol
\( CH_3OH(I)+\frac 32O_2(g)→CO_2(g)+2H_2O(I)\)
the amount of heat produced as measured by bomb calorimeter is \(726\) kJ mol–1 at \(27°C\). The enthalpy of combustion for the reaction is \(x \ kJ mol^{–1}\), where \(x\) is ______ . (Nearest integer)
(Given: \(R= 8.3 \ JK^{–1}mol^{–1}\))
Product ‘A’ of the following sequence of reactions is                                       
\(Ethylbenzene \xrightarrow[{(b)Cl_2,Δ;(c) alc.KOH}]{ (a)Br_2,Fe }\)‘ \(\;  \;\; \;\;A′\\major Product\)
Decarboxylation of all six possible forms of diaminobenzoic acid \(C_6H_3(NH_2)2COOH\) yields three products A, B and C. Three acids give a product ‘A’, two acids give a product ‘B’ and one acid gives a product ‘C’. The melting point of product ‘C’ is
A 0.5 percent solution of potassium chloride was found to freeze at –0.24°C. The percentage dissociation of potassium chloride is ______. (Nearest integer)
(Molal depression constant for water is 1.80 K kg mol–1 and 
molar mass of KCl is 74.6 g mol–1)
Which is true about Buna-N?
Given below are two statements :
Statement I: Maltose has two\(α-D-glucose\) units linked at \(C_1\) and \(C_4\) and is a reducing sugar.
Statement II: Maltose has two monosaccharides : 
\(α-D-glucose\) and \(β-D-glucose\) linked at \(C_1\) and \(C_6\) and it is a non-reducing sugar.
In the light of the above statements, choose the correct answer from the options given below.
Match List I with List II.
 List I (Anion) List II (gas evolved on reaction with dil \(H_2SO_4\))
A.\(CO_3^{ 2−}\)I.Colourless gas which turns lead acetate paper black.
B.\(S^{2–}\)II.Colourless gas which turns acidified potassium dichromate solution green
C.\(SO_3^{ 2−}\)III.Brown fumes which turns acidified KI solution containing starch blue.
D.\(NO_2^{−}\)IV.Colourless gas evolved with brisk effervescence, which turns lime water milky.
Choose the correct answer from the options given below:
50 mL of 0.1 M CH3COOH is being titrated against 0.1 M NaOH. When 25 mL of NaOH has been added, the pH of the solution will be ____ × 10–2. (Nearest integer)
(Given : pKa (CH3COOH) = 4.76)
log 2 = 0.30
log 3 = 0.48
log 5 = 0.69
log 7 = 0.84
log 11 = 1.04
116 g of a substance upon dissociation reaction, yields 7.5 g of hydrogen, 60 g of oxygen and 48.5 g of carbon. Given that the atomic masses of H, O and C are 1, 16 and 12, respectively. The data agrees with how many formulae of the following? _______
A. \(CH_3COOH\)
B. \(HCHO\)
C. \(CH_3OOCH_3\)
D. \(CH_3CHO\)
A flask is filled with equal moles of A and B. The half lives of A and B are 100 s and 50 s respectively and are independent of the initial concentration. The time required for the concentration of A to be four times that of B is ________s.
(Given : In 2 = 0.693)
Consider the following set of quantum numbers.
\(n \,|\, m_|\)
A. 3 3 –3
B. 3 2 –2
C. 2 1 +1
D. 2 2 +2
The number of correct sets of quantum numbers is _____.
2.0 g of H2 gas is adsorbed on 2.5 g of platinum powder at 300 K and 1 bar pressure. The volume of the gas adsorbed per gram of the adsorbent is _____ mL.
(Given : R= 0.083 L bar K–1 mol–1)
\(BeO\) reacts with \(HF\) in presence of ammonia to give \([A]\) which on thermal decomposition produces \([B]\) and ammonium fluoride. Oxidation state of Be in \([A]\) is _______
The spin-only magnetic moment value of the most basic oxide of vanadium among \(V_2O_3, V_2O_4\) and \(V_2O_5\) is ______B.M. (Nearest integer)
If \(y(x) = (x^x)^x, \quad x > 0\), then \(\frac{d^2x}{dy^2} + 20\) at \(x = 1\) is equal to __________.
All resistances in figure are 1 Ω each. The value of current ‘I‘ is \((\frac{a}{5})\) A. The value of a is _______.
value of current