List of top Chemistry Questions asked in JEE Main

Inert gases have positive electron gain enthalpy Its correct order is

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

	Column I		Column II
(A).	Biodegradable	(P).	Polyacrylonitrie
(B).	Synthetic	(Q).	PHBV
(C).	Natural	(R).	Dacron
(D).	Polyester	(S).	Rubber

The magnetic moment is measured in Bohr Magneton (BM).
Spin only magnetic moment of Fe in [Fe(H₂O)₆] ³⁺ and [Fe(CN)₆] ^3– complexes respectively is:

The major products ' A ' and ' B ', respectively, are

For micelle formation, which of the following statements are correct?
(A) Micelle formation is an exothermic process
(B) Micelle formation is an endothermic process
(C) The entropy change is positive
(D) The entropy change is negative

Statement I : Dipole moment is a vector quantity and by convention it is depicted by a small arrow with tail on the negative centre and head pointing towards the positive centre
Statement II : The crossed arrow of the dipole moment symbolizes the direction of the shift of charges in the molecules.
In the light of the above statements, choose the most appropriate answer from the options given below:

Match items of Row I with those of Row II

According to MO theory the bond orders for $O_2^{2−},CO\,\, \text {and} \,\,NO^+$ respectively, are

Which of the following statements is correct about freons?

CH₃CH₂-Br $\overrightarrow{Acetone}^{NaI}$ CH₃-CH₂-I+NaBr
Which of the following statement is correct ?

Given below are two statements : one is labelled as Assertion (A) and the other is labelled as Reason (R)
Assertion (A): $Cu ^{2+}$ in water is more stable than $Cu ^{+}$
Reason (R): Enthalpy of hydration for $Cu ^{2+}$ is much less than that of $Cu ^{+}$
In the light of the above statements, choose the correct answer from the options given below :

Group–13 elements react with $ O_2 $ in amorphous form to form oxides of type $ M_2O_3 $ (M = element). Which among the following is the most basic oxide?

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

$[Co(NH_3)_6]^{3+} \text{is} $ ________$\text{hybridised and}$________

Given below are two statements : one is labelled as Assertion (A) and the other is labelled as Reason (R)
Assertion (A) : An aqueous solution of $KOH$ when used for volumetric analysis, its concentration should be checked before the use
Reason (R) : On aging,$KOH$ solution absorbs atmospheric $CO _2$
In the light of the above statements, choose the correct answer from the options given below :

Given below are two statements : one is labelled as Assertion (A) and the other is labelled as Reason (R)
Assertion (A): $\alpha$-halocarboxylic acid on reaction with dil $NH _3$ gives good yield of $\alpha$-aminocarboxylic acid whereas the yield of amines is very low when prepared from alkyl halides
Reason (R): Amino acids exist in zwitter ion form in aqueous medium
In the light of the above statements, choose the correct answer from the options given below :

In figure, a straight line is given for Freundrich Adsorption$(y=3 x+2505)$ The value of $\frac{1}{ n }$and$\log K$are respectively

$O - O$ bond length in $H _2 O _2$ is X than the $O - O$ bond length in $F _2 O _2$The $O - H$ bond length in $H _2 O _2$is Y than that of the$O - F$ bond in $F _2 O _2$Choose the correct option for $\underline{X} and \underline{Y}$ from those given below :

Which one of the following statements is correct for electrolysis of brine solution?

When $Cu ^{2+}$ ion is treated with $KI$, a white precipitate, $X$ appears in solution The solution is titrated with sodium thiosulphate, the compound $Y$ is formed $X$ and $Y$ respectively are

Identify $X , Y$ and $Z$ in the following reaction (Equation not balanced) $ClO + NO _2 \rightarrow \underline{ X } \stackrel{ H _2 O }{\longrightarrow} \underline{ Y }+\underline{Z}$

Adding surfactants in non polar solvent, the micelles structure will look like

The methods NOT involved in concentration of ore are
A Liquation
B Leaching
C Electrolysis
D Hydraulic washing
E Froth floatation
Choose the correct answer from the options given below :

A protein ' $X$ ' with molecular weight of $70,000 u$, on hydrolysis gives amino acids One of these amino acid is

In Dumas method for the estimation of $N _2$, the sample is heated with copper oxide and the gas evolved is passed over :