List of top Chemistry Questions asked in JEE Main

Given below are two statements : Statement I : On heating with \(KHSO _4\), glycerol is dehydrated and acrolein is formed 
Statement II : Acrolein has fruity odour and can be used to test glycerol's presence Choose the correct option

Refining using liquation method is the most suitable for metals with :

Which of the following can be used to prevent the decomposition of $H _2 O _2$ ?

Reaction of \(BeCl _2\) with \(LiAlH _4\) gives: Choose the correct answer from options given below : 

1. \(AlCl _3\)
2. \(BeH _2\)
3. \(LiH\)
4. \(LiCl\)
5. \(BeAlH _4\)
    

Borazine, also known as inorganic benzene, can be prepared by the reaction of 3-equivalents of "$X$" with 6-equivalents of "Y". "X" and "Y", respectively are :

The difference in the reaction of phenol with bromine in chloroform and bromine in water medium is due to :

Which technique among the following, is most appropriate in separation of a mixture of $100\, mg$ of $p$-nitrophenol and picric acid ?

$\dot{ C } l + CH _4 \rightarrow A + B$. $A$ and $B$ in the above atmospheric reaction step are

The dark purple colour of $KMnO _4$ disappears in the titration with oxalic acid in acidic medium. The overall change in the oxidation number of manganese in the reaction is :

During the denaturation of proteins, which of these structures will remain intact ?

The photochemical smog does not generally contain :

Choose the correct order of density of the alkali metals :

The compound(s) that is(are) removed as slag during the extraction of copper is : 

1. \(CaO\) 
2.  \(FeO\) 
3.  \(Al _2 O _3\) 
4.  \(ZnO\)
5.  \(NiO\) 
   Choose the correct answer from the options given below :

Given below are two statements :
Statement I: In polluted water values of both dissolved oxygen and BOD are very low.
Statement II: Eutrophication results in decrease in the amount of dissolved oxygen.
In the light of the above statements, choose the most appropriate answer from the options given below :

In Freundlich adsorption isotherm, slope of AB line is :

Which of the following reaction/s will not give \(p-\) aminoazobenzene?

(A) $HOCl + H _{2} O _{2} \rightarrow H _{3} O ^{+}+ Cl ^{-}+ O _{2}$
(B) $I _{2}+ H _{2} O _{2}+2 OH ^{-} \rightarrow 2 I ^{-}+2 H _{2} O + O _{2}$
Choose the correct option.

Which of the following equation depicts the oxidizing nature of $H _{2} O _{2} ?$

Which of the following are isostructural pairs? A. $SO _{4}^{2-}$ and $CrO _{4}^{2-}$ B. $SiCl _{4}$ and $TiCl _{4}$ C. $NH _{3}$ and $NO _{3}^{-}$ D. $BCl _{3}$ and $BrCl _{3}$ $BCl _{3}$ and $BrCl _{3}$

According to Bohr's atomic theory :- (A) Kinetic energy of electron is $\propto \frac{ Z ^{2}}{ n ^{2}}$. (B) The product of velocity (v) of electron and principal quantum number (n), 'vn' $\propto Z ^{2}$. (C) Frequency of revolution of electron in an orbit is $\propto \frac{ Z ^{3}}{ n ^{3}}$. (D) Coulombic force of attraction on the electron is $\propto \frac{ Z ^{3}}{ n ^{4}}$. Choose the most appropriate answer from the options given below:

The correct order of bond dissociation enthalpy of halogens is :

Out of the following, which type of interaction is responsible for the stabilisation of $\alpha$ -helix structure of proteins?

Calgon is used for water treatment. Which of the following statement is $NOT$ true about Calgon?

Complete combustion of $1.80 g$ of an oxygen containing compound $\left( C _{ x } H _{ y } O _{2}\right)$ gave $2.64 g$ of $CO _{2}$ and $1.08 g$ of $H _{2} O$. The percentage of oxygen in the organic compound is:

Given below are two statements : Statement I : Colourless cupric metaborate is reduced to cuprous metaborate in a luminous flame. Statement II : Cuprous metaborate is obtained by heating boric anhydride and copper sulphate in a non-luminous flame. In the light of the above statements, choose the most appropriate answer from the options given below.