List of top Chemistry Questions asked in JEE Main

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

During the qualitative analysis of \( SO_{3}^{-2}\) using dilute H2SO4, SO2 gas evolved which turns K2Cr2O7 solution (acidified H2SO4)

Formation of photochemical smog involves the following reaction in which A, B, and C are respectively:
\(\text{NO}_2 \xrightarrow{h\nu} \text{A} + \text{B}\)
\(\text{B} + \text{O}_2 \rightarrow \text{C}\)
\(\text{A} + \text{C} \rightarrow \text{NO}_2 + \text{O}_2\)
Choose the correct answer from the options given below:

Find out the major product for the following reaction.
Find out the major product for the following reaction.
The correct reaction profile diagram for a positive catalyst reaction .
In Hall - Heroult process, the following is used for reducing Al2O3 :-
Major product 'P' formed in the following reaction is:
Major product 'P' formed in the following reaction is:
The product (P) formed from the following multistep reaction is:
The product (P) formed from the following multistep
The statement/s which are true about antagonists from the following is/are:
A. They bind to the receptor site.
B. Get transferred inside the cell for their action.
C. Inhibit the natural communication of the body.
D. Mimic the natural messenger.
Choose the correct answer from the options given below:
Coagulating value of the electrolytes AlCl3 and NaCl for As2S3 are 0.09 and 50.04 respectively. The coagulating power of AlCl3 is x times the coagulating power of NaCl. The value of x is ______ .
In the following reactions, the total number of oxygen atoms in X and Y is _______
Na2O + H2O → 2X
Cl2O7 + H2O → 2Y
The major product P formed in the given reaction is:
The major product P formed
Incorrect method of preparation for alcohols from the following is:
In the reaction given below :
The Product X is:
The Product ‘X’ is:
Buna-S can be represented as:
The reaction used for preparation of soap from fat is :
\(A(g) ⇋ 2B(g) + C(g)\)
For the given reaction, if the initial pressure is 450 mm Hg and the pressure at time t is 720 mm Hg at a constant temperature T and constant volume V. The fraction of A(g) decomposed under these conditions is \(x × 10^{–1}\). The value of x is _____ . (nearest integer)
What is the purpose of adding gypsum to cement? 
For a reversible reaction A ⇌ B, the ΔHforward reaction = 20 kJ mol-1. The activation energy of the uncatalysed forward reaction is 300 kJ mol-1. When the reaction is catalysed keeping the reactant concentration same, the rate of the catalysed forward reaction at 27°C is found to be same as that of the uncatalysed reaction at 327°C. The activation energy of the cataysed backward reactoion is ____ kJ mol-1.

\(H_2O_2\) behave like reducing agent in which of the following reactions:

The Lewis acid character of boron tri halides follows the order :

Match List I with List II 
Molecules/Ions
Choose the correct answer from the options given below:

Which of the following represents the correct order of metallic character of the given elements?
Match List I with List II
LIST ILIST II
AChlorophyll1\(Na _2 CO _3\)
BSoda ash2\(CaSO _4\)
CDentistry, Ornamental work3\(Mg ^{2+}\)
DUsed in white washing4\(Ca ( OH )_2\)
Compound A reacts with $NH _4 Cl$ and forms a compound B Compound B reacts with $H _2 O$ and excess of $CO _2$ to form compound $C$ which on passing through or reaction with saturated $NaCl$ solution forms sodium hydrogen carbonate Compound $A , B$ and $C$, are respectively