List of top Chemistry Questions asked in JEE Main

Given below are two statements :
Statement I : Emulsions of oil in water are unstable and sometimes they separate into two layers on standing.
Statement II : For stabilisation of an emulsion, excess of electrolyte is added.
In the light of the above statements, choose the most appropriate answer from the options given below :
Match List - I with List - II :
List - IList - II
(A)Sphalerite(I)\(\mathrm{FeCO_3}\)
(B)Calamine(II)\(\mathrm{PbS}\)
(C)Galena(III)\(\mathrm{ZnCO_3}\)
(D)Siderite(IV)\(\mathrm{ZnS}\)
Choose the most appropriate answer from the options given below :

The major product of the above reactions is :
The most stable trihalide of nitrogen is :
Which of the following is an example of conjugated diketone?
A polysaccharide 'X' on boiling with dil \(\mathrm{H_2SO_4}\) at 393 K under 2-3 atm pressure yields 'Y'. 'Y' on treatment with bromine water gives gluconic acid. 'X' contains \(\beta\)-glycosidic linkages only. Compound 'X' is :
Two statements are given below :
Statement I : The melting point of monocarboxylic acid with even number of carbon atoms is higher than that of with odd number of carbon atoms acid immediately below and above it in the series.
Statement II : The solubility of monocarboxylic acids in water decreases with increase in molar mass.
Choose the most appropriate option :
In the given reaction sequence, the major product 'C' is :
Match List - I with List - II :
List - IList - II
(A)\([\mathrm{PtCl_4}]^{2-}\)(I)\(sp^3d\)
(B)\(\mathrm{BrF_5}\)(II)\(d^2sp^3\)
(C)\(\mathrm{PCl_5}\)(III)\(dsp^2\)
(D)\([\mathrm{Co(NH_3)_6}]^{3+}\)(IV)\(sp^3d^2\)
Choose the most appropriate answer from the options given below :
For a reaction at equilibrium
\(\mathrm{A(g)} \rightleftharpoons \mathrm{B(g)} + \frac{1}{2}\mathrm{C(g)}\)
the relation between dissociation constant (K), degree of dissociation (\(\alpha\)) and equilibrium pressure (p) is given by :
If a rocket runs on a fuel (\(\mathrm{C_{15}H_{30}}\)) and liquid oxygen, the weight of oxygen required and \(\mathrm{CO_2}\) released for every litre of fuel respectively are :
(Given : density of the fuel is 0.756 g/mL)
Given below are the oxides:
\(\mathrm{Na_2O,\ As_2O_3,\ N_2O,\ NO}\) and \(\mathrm{Cl_2O_7}\)
Number of amphoteric oxides is :
Consider the following pairs of electrons
(A) (a) n = 3, \(l\) = 1, \(m_l\) = 1, \(m_s\) = \(+\frac12\)
   (b) n = 3, \(l\) = 2, \(m_l\) = 1, \(m_s\) = \(+\frac12\)
(B) (a) n = 3, \(l\) = 2, \(m_l\) = \(-2\), \(m_s\) = \(-\frac12\)
    (b) n = 3, \(l\) = 2, \(m_l\) = \(-1\), \(m_s\) = \(-\frac12\)
(C) (a) n = 4, \(l\) = 2, \(m_l\) = 2, \(m_s\) = \(+\frac12\)
    (b) n = 3, \(l\) = 2, \(m_l\) = 2, \(m_s\) = \(+\frac12\)
The pairs of electrons present in degenerate orbitals is/are :
The major product of the following reaction is :

\(\mathrm{PhS^{\ominus}\ Na^{\oplus}}\) in DMF
Reaction 1: Aniline \((\mathrm{C_6H_5NH_2})\) with \(\mathrm{Br_2}\) (excess) in \(\mathrm{H_2O}\) gives A (Major Product).
Reaction 2: Aniline with (i) \((\mathrm{CH_3CO})_2\mathrm{O}\); (ii) \(\mathrm{Br_2}\), \(\mathrm{CH_3COOH}\); (iii) HCl gives B (Major Product).
Consider the above reactions, the product A and product B respectively are
The correct order of energy of absorption for the following metal complexes is :
A : \([\mathrm{Ni(en)_3}]^{2+}\), B : \([\mathrm{Ni(NH_3)_6}]^{2+}\), C : \([\mathrm{Ni(H_2O)_6}]^{2+}\)
The major product of the following reaction is

(Substrate: 1-methoxy-2-nitrobenzene (2-nitroanisole), \(\mathrm{OCH_3}\) and \(\mathrm{NO_2}\) on adjacent ring carbons.) Reagents: (i) Na/liq. \(\mathrm{NH_3}\); (ii) \(\mathrm{CH_3CH_2OH}\).

[Et is \(-\mathrm{C_2H_5}\)]
Reaction: the substrate \(\mathrm{EtO-C(=O)-CH_2-}\)(cyclopentene ring, 1,3-disubstituted, C=C in the ring)\(\mathrm{-CH_2CH_2CN}\) is treated with (i) DIBAL-H, (ii) \(\mathrm{H_2O}\).
Consider the above reaction and predict the major product.
Match List - I with List - II.
List - IList - II
(A)\(\mathrm{C_6H_5COCl}\ \xrightarrow{\mathrm{H_2,\ Pd\text{-}BaSO_4}}\ \mathrm{C_6H_5CHO}\) [structures drawn in the paper](I)Gatterman Koch reaction
(B)\(\mathrm{CH_3-CN}\ \xrightarrow[\mathrm{H_3O^+}]{\mathrm{SnCl_2/HCl}}\ \mathrm{CH_3-CHO}\)(II)Etard reaction
(C)\(\mathrm{C_6H_5CH_3}\ \xrightarrow[\mathrm{H_3O^+}]{\mathrm{CrO_2Cl_2}}\ \mathrm{C_6H_5CHO}\) [structures drawn in the paper](III)Stephen reaction
(D)\(\mathrm{C_6H_6}\ \xrightarrow[\mathrm{AlCl_3\ (anhyd)}]{\mathrm{CO,\ HCl}}\ \mathrm{C_6H_5CHO}\) [structures drawn in the paper](IV)Rosenmund reaction
Choose the correct answer from the options given below :
\(200\ \mathrm{mL}\) of \(0.01\ \mathrm{M}\ \mathrm{HCl}\) is mixed with \(400\ \mathrm{mL}\) of \(0.01\ \mathrm{M}\ \mathrm{H_2SO_4}\). The \(\mathrm{pH}\) of the mixture is _________.
Given: \(\log2=0.30,\ \log3=0.48,\ \log5=0.70,\ \log7=0.84,\ \log11=1.04\)

100 mL of 0.3 M acetic acid is shaken with 0.8 g of wood charcoal. The final concentration of acetic acid in the solution after adsorption is 0.125 M. The mass of acetic acid adsorbed per gram of carbon is _____________ \( \times \) 10\( - \)4 g.

(Given : Molar mass of acetic acid = 60 g mol\( - \)1)

How many of the following drugs belong to the tranquilizer class _____________ ?

Veronal, Luminal, Propanal, Seconal

An element X has a body centred cubic (bcc) structure with a cell edge of 200 pm. The density of the element is 5 g cm\( - \)3. The number of atoms present in 300 g of the element X is _______________.

Given : Avogadro constant, NA = 6.0 \( \times \) 1023 mol\( - \)1.

Correct statement about alkali metal oxides is :

Match List - I with List - II :

List-I List-II
(a) Sodium hydride (i) Lewis acid
(b) Silane (ii) Saline hydride
(c) Vanadium hydride (iii) Molecular hydride
(d) Aluminium hydride (iv) Non-stoichiometric hydride

Correct answer is :