List of top Chemistry Questions asked in JEE Main

The reaction of $H _2 O _2$ with potassium permanganate in acidic medium leads to the formation of mainly:

Which of the following has the highest hydration energy?

Consider the following reaction sequence: \([CaCl_2 + Na_2CO_3 → X+Y] → Z\)

Match the terms in Column-I with their description in Column-II and choose the correct option:

 Column 1(Type of hydride) Column II
A.Electron1.MgH2
B.Electron precise2.HF
C.Electron rich3.CH4
D.Saline Hydride4.B2H6
Enthalpy of adsorption and enthalpy of formation of micelle are respectively
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

Given below are two statements, one is labelled as Statement-1 and the other is labelled as Statement-2: Statement-1: Sulphides are converted into oxide first. Statement-2: Because oxides can be reduced easily. In the light of the above statements, choose the correct answer from the options given below

S1: Be+2 has higher SRP than other alkaline earth metals.
S2: Be+2 has higher hydration energy and greater △aH (atomisation enthalpy) than other alkaline earth metals.

Given below are two statements :
Statement I: SbCI, is more covalent than SbCI3
Statement II: The higher oxides of halogens also tend to be more stable than the lower ones. 
In the light of the above statements, choose the most appropriate 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 
Product [X] formed in the above reaction is:
Product [X] formed in the above reaction is:
A metal chloride contains 55% by mass of chlorine. 100 mL of vapours gives 0.57 gm of chlorine at STP. Calculate the molecular mass of metal chloride. (Nearest integer)
correct sequence of reagents to be added is
In the above conversion the correct sequence of reagents to be added is
The specific conductance of 0.0025 M acetic acid is \(5 × 10^{–5} S\ cm^{–1}\) at a certain temperature. The dissociation constant of acetic acid is ___________ \(× 10^{–7}.\) (Nearest integer) Consider limiting molar conductivity of \(CH_3COOH\) as \(400\  S cm^2 mol^{–1}\).
Lime reacts exothermally with water to give ‘A’ which has low solubility in water. Aqueous solution of ‘A’ is often used for the test of CO2 , a test in which insoluble B is formed. If B is further reacted with CO2 then soluble compound is formed ‘A’ is
For the given reaction
The total number of possible products formed by tertiary carbocation
The total number of possible products formed by tertiary carbocation of A is____.
If the boiling points of two solvents X and Y (having same molecular weights) are in the ratio 2:1 and their enthalpy of vaporizations are in the ratio 1:2, then the boiling point elevation constant of X is m times the boiling point elevation constant of Y. The value of m is_______ (nearest integer).
Compound A from the following reaction sequence is 
Br2 , C S 2 0 − 5 ° C 0 − 5 ° 𝐶 → 𝐵 𝑟 2 , 𝐶 𝑆 2 B. N a N O 2 / H C l
0.400 g of an organic compound (X) gave 0.376 g of AgBr in Carius method for estimation of bromine. % of bromine in the compound (X) is____
(Given: Molar mass AgBr=188g mol-1)
A(g) → 2B(g) + C(g) is a first order reaction. The initial pressure of the system was found to be 800 mm Hg which increased to 1600 mm Hg after 10 min. The total pressure of the system after 30 min will be ___mm Hg. (Nearest integer)
20 mL of 0.1 M NaOH is added to 50 mL of 0.1 M acetic acid solution. The pH of the resulting solution is____ x 10-2 (Nearest integer) 
Given: pKa (CH3COOH) = 4.76 
log 2 = 0.30 
log 3 = 0.48
The orbital angular momentum of an electron in 3s orbital is  \(\frac{xh}{2π}\) The value of x is___.
1g of a carbonate (M2CO3) on treatment with excess HCl produces 0.01 mol of CO2 .The molar mass of M2CO3 is g mol-1. (Nearest integer)
Given below are two statements: one is labelled as Assertion A and the other is labelled as Reason R:
Assertion A: 3.1500 g of hydrated oxalic acid dissolved in water to make 250.0 mL solution will result in 0.1 M oxalic acid solution.
Reason R: Molar mass of hydrated oxalic acid is 126 g mol–1.
In the light of the above statements, choose the correct answer from the options given below.
ClF5 at room temperature is: