List of top Chemistry Questions asked in JEE Main

CH3CH2-Br \(\overrightarrow{Acetone}^{NaI}\) CH3-CH2-I+NaBr
Which of the following statement is correct ? 
Consider the reaction \(Cu^{2+} + X^- → Cu_2X_2 + X_2\).
X2 will be predominantly?
The pair of lanthanides will exceptionally high 3rd ionisation enthalpy than neighbouring elements:
Select the correct order of electronegativity of the elements: B, C, At, S
XeF$_4$ reacts with SbF$_5$ to form:
\[ [\text{XeF}_m]^{n+}[\text{SbF}_y]^{z-} \] What is $m+n+y+z$?
Incorrect statement about Borazine is:
Consider the following:
  1. D.D.T.
  2. Aldrin
  3. Sodium arsenite
  4. Sodium chlorate
How many of these are pesticides?
How many statements are correct:
  1. If there is no relation between rate constant and temperature, then activation energy is negative.
  2. If the activation energy is zero, rate constant is temperature independent.
  3. If rate constant increases with increase of temperature, activation energy is positive.
  4. If rate constant decreases with increase in temperature, activation energy is negative.
What happens when lyophilic sol is added to lyophobic sol. prevention from coagulation precipitation emulsion electrophoresis
Which of the following shows an incorrect method of refining?

Given below are two statements: one is labeled as Assertion (A) and the other is labeled as Reason (R).
Assertion (A): Acidic nature follows the order:

Reason (R): F is a better electron-withdrawing group than Cl
In the light of the above statements, write the detailed answer:

Predict expression from α in terms of \(K_{eq}\) and concentration C : 

\(A_2 B_3(aq) \leftrightharpoons 2{A_3} (aq)+3B_{{2-}}(aq)\)

Polymer which is named as orlon is:
Reaction of $BeO$ with ammonia and hydrogen fluoride gives A which on thermal decomposition gives $BeF _2$ and $NH _4 F$ What is ' $A ^{\prime}$ ?

How many bromo products are formed when ethane is reacted with excess of Br2 on heating?

Order of Covalent bond:
A. $KF > KI ; LiF > KF$ 
B. $KF < KI ; LiF > KF$ 
C. $SnCl _4> SnCl _2 ; CuCl > NaCl$ 
D. $LiF > KF ; CuCl <NaCl$
E. $KF < KI ; CuCl > NaCl$ 
Choose the correct answer from the options given below:
Which of the following have square pyramidal structure?
Match the terms in Column-I with their description in Column-II and choose the correct option :
Column IColumn II
(i)Vitamin AaBeri-beri
(ii)Vitamin C (Ascorbic acid)bCheilosis
(iii)RiboflavincXerophthalmia
(iv)ThiaminedScurvy

Photochemical smog found mainly in 


Product (P) and (Q) are respectively
Number of ambidentate ligands in given complex [M(en)(SCN)4]:

A binary compound has Y-atoms forming FCC unit cell and another type of X-atoms occupying \(\frac{1}{3}\)rd of tetrahedral voids. Find out the molecular formula of the compound

 

How many moles of Ba3(PO4)2 will be formed by the reaction of 5 moles of BaCl2 and 3 moles of Na3(PO4).

Match the terms in Column-I with their description in Column-II and choose the correct option:
Column I (Chemical reactions)Column II (Enzymes used)
(i)Glucose → CO2 + EthanolaPepsin
(ii)Sucrose→Glucose + Fructose bDiastase
(iii)Starch →Maltose cZymase
(iv)Protein→Amino acids dInvertase
If the radius of ground state hydrogen is 51 pm, find out the radius of 5th orbit of Li2+ ions. (closest integer)