List of top Chemistry Questions asked in JEE Main

(a) Baryte,
(b) Galena, 
(c) Zinc blende and 
(d) Copper pyrites. 
How many of these minerals are sulphide based?

A box contains 0.90 g of liquid water in equilibrium with water vapour at 27°C. The equilibrium vapour pressure of water at 27°C is 32.0 Torr. When the volume of the box is increased, some of the liquid water evaporates to maintain the equilibrium pressure. 
If all the liquid water evaporates, then the volume of the box must be ______ litre. [nearest integer]
(Given : R = 0.082 L atm K^–1 mol^–1] (Ignore the volume of the liquid water and assume water vapours behave as an ideal gas.)

In the titration of KMnO₄ and oxalic acid in acidic medium, the change in oxidation number of carbon at the end point is _____.

When 200 mL of 0.2 M acetic acid is shaken with 0.6 g of wood charcoal, the final concentration of acetic acid after adsorption is 0.1 M. The mass of acetic acid adsorbed per gram of carbon is _____ g.

Which amongst the following is not a pesticide?

Given below are two statements :
Statement-I : For KI, molar conductivity increases steeply with dilution.
Statement-II : For carbonic acid, molar conductivity increases slowly with dilution.
In the light of the above statements, choose the correct answer from the options given below :

Kjeldahl’s method was used for the estimation of nitrogen in an organic compound. The ammonia evolved from 0.55 g of the compound neutralised 12.5 mL of 1 M H₂SO₄ solution. The percentage of nitrogen in the compound is _____. (Nearest integer)

The structure of protein that is unaffected by heating is

Statement-I: An alloy of lithium and magnesium is used to make aircraft plates. 

Statement-II: The magnesium ions are important for cell-membrane integrity. 

In the light of the above statements, choose the correct answer from the options given below:

Which will have the highest enol content?

The plot of pH-metric titration of weak base NH₄OH vs strong acid HCl looks lie:

The correct order of melting point is

In the flame test of a mixture of salts, a green flame with blue centre was observed. Which one of the following cations may be present?

At \(298\ K\), the equilibrium constant is \(2 × 10^{15}\) for the reaction:
\(Cu(s)+2Ag+(Aq)⇌Cu^{2+}(aq)+2Ag(s)\)
The equilibrium constant for the reaction:
\(\frac 12Cu^{2+}(aq)+Ag(s)+(Aq)⇌\frac 12Cu(s)+Ag^+(aq)\) is \(x \times10^{-8}\).
The value of \(x\) is ______ . (Nearest integer)

Which statement is NOT correct for p-toluenesulphonyl chloride?

The correct stability order of the following diazonium salt is

White phosphorus reacts with thionyl chloride to give

The solubility product of a sparingly soluble salt \(A_2X_3\) is \(1.1 × 10^{–23}\). If the specific conductance of the solution is \(3×10^{–5}\) S m^–1, the limiting molar conductivity of the solution is \(x×10^{–3}\) S m² mol^–1. The value of x is _______.

A 10 g mixture of hydrogen and helium is contained in a vessel of capacity 0.0125 m³ at 6 bar and 27°C. The mass of helium in the mixture is _______ g. (nearest integer)
Given : R = 8.3 J K^–1 mol^–1
(Atomic masses of H and He are 1 u and 4 u, respectively)

Match List-I with List-II

	(Polymer)		(Used in)
A.	Bakelite	i	Radio and television cabinets
B.	Glyptal	ii	Electrical switches
C.	PVC	iii	Paints and Lacqures
D.	Polystyrene	iv	Water pipes

Choose the correct answer from the options given below: