List of top Chemistry Questions asked in JEE Main

Given below are two statements, one is Assertion (A) and other is Reason (R).

Assertion (A): Natural rubber is a linear polymer of isoprene called cis-polyisoprene with elastic properties.
Reason (R): The cis-polyisoprene molecules consist of various chains held together by strong polar interactions with coiled structure.

In the light of the above statements, choose the correct one from the options given below:

The equation k = (6.5 × 1012s–1)e–26000K/T is followed for the decomposition of compound A. The activation energy for the reaction is ______ kJ mol–1. [nearest integer]
(Given : R = 8.314 J K–1 mol–1]
The cell potential for the given cell at 298 K \(\text{Pt} | \text{H}_2 \text{(g, 1 bar)} | \text{H}^+ \text{(aq)} || \text{Cu}^{2+} \text{(aq)} | \text{Cu(s)}\) is 0.31 V. The pH of the acidic solution is found to be 3, whereas the concentration of Cu2+ is 10–x M. The value of x is _____.
(Given : \(E^{Θ}_{Cu^{2+}/Cu}\) = 0.34 V and \(\frac{2.303RT}{F}\) = 0.06 V)
Hex-4-ene-2-ol on treatment with PCC gives ‘A’ on reaction with sodium hypoiodite gives ‘B’, which on further heating with soda lime gives ‘C’. The compound ‘C’ is
Some gases are responsible for heating of atmosphere (green house effect). Identify from the following the gaseous species which does not cause it.
When sugar ‘X’ is boiled with dilute H2SO4 in alcoholic solution, two isomers ‘A’ and ‘B’ are formed. ‘A’ on oxidation with HNO3 yields saccharic acid whereas ‘B’ is laevorotatory. The compound ‘X’ is :
\(PCl_5\) dissociates as
\(PCl_5(g) ⇌ PCl_3(g)+ Cl_2(g)\)
\(5\) moles of \(PCl_5\) are placed in a \(200\) litre vessel which contains \(2\) moles of \(N_2\) and is maintained at \(600\ K\). The equilibrium pressure is \(2.46\) atm. The equilibrium constant Kp for the dissociation of \(PCl_5\) is ______ \(× 10^{–3}\). (nearest integer) 
(Given: \(R = 0.082\) L atm K–1 mol–1; Assume ideal gas behaviour)

Given are two statements one is labelled as Assertion A and other is labelled as Reason R.

Assertion A : Magnesium can reduce Al2O3 at a temperature below 1350°C, while above 1350°C aluminium can reduce MgO.
Reason R : The melting and boiling points of magnesium are lower than those of aluminium.

In light of the above statements, choose the most appropriate answer from the options given below :

A primary aliphatic amine on reaction with nitrous acid in cold (273 K) and there after raising temperature of reaction mixture to room temperature (298 K), gives
Number of complexes which will exhibit synergic bonding amongst, \([Cr(CO)_6]\), \([Mn(CO)_5]\) and \([Mn_2(CO)_{10}]\) is ________.
Consider the following reaction: 
A + alkali → B (Major Product)
If B is an oxoacid of phosphorus with no P-H bond, then A is
In Carius method of estimation of halogen, 0.45 g of an organic compound gave 0.36 g of AgBr. Find out the percentage of bromine in the compound.
(Molar masses: AgBr = 188 g mol–1; Br = 80 g mol–1)
What will be the major product of the following sequence of reactions?
\(n−Bu−≡ \xrightarrow[{(ii)Lindlar catalyst, H_2}]{(i)n-BuLi,n-C_5H_{11}Cl}\)
The products obtained during treatment of hard water using Clark’s method are:
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:
Two isomers (A) and (B) with Molar mass 184 g/mol and elemental composition C, 52.2%; H, 4.9 % and Br 42.9% gave benzoic acid and p-bromobenzoic acid, respectively on oxidation with KMnO4. Isomer ‘A’ is optically active and gives a pale yellow precipitate when warmed with alcoholic AgNO3. Isomers ‘A’ and ‘B’ are, respectively.

The correct order of reduction potentials of the following pairs is

(A)\( \frac{Cl_2}{Cl^–}\)

(B)\( \frac{I_2}{I^–}\)

(C) \(\frac{Ag^+}{Ag}\)

(D) \(\frac{Na^+}{Na}\)

(E) \(\frac{Li^+}{ Li}\)

Choose the correct answer from the options given below:

The spin-only magnetic moment value of the most basic oxide of vanadium among \(V_2O_3, V_2O_4\) and \(V_2O_5\) is ______B.M. (Nearest integer)
The Zeta potential is related to which property of colloids?
Arrange the following in increasing order of their covalent character. 
A. \(CaF_2\) 
B. \(CaCl_2\) 
C. \(CaBr_2\) 
D. \(Cal_2\)

In the given reaction

Fig. 

the number of sp2 hybridised carbon(s) in compound ‘X’ is _____.

(a)CoCl3⋅4NH3,(b)CoCl3⋅5NH3,(c)CoCl3.6NH3 and (d)CoCl(NO3)2⋅5NH3.Number of complex(es) which will exist in cis-trans form is/are______.
Match List I with List II.
List I Pollutant List II Disease/ sickness
A. Sulphate (> 500 ppm)I. Methemoglobinemia
B. Nitrate (> 50 ppm)II. Brown mottling of teeth
C. Lead (> 50 ppb)III. Laxative effect
D. Fluoride (> 2ppm)IV. Kidney damage
Choose the coned answer from the options given below:
The osmotic pressure exerted by a solution prepared by dissolving 2.0 g of protein of molar mass 60 kg mol–1 in 200 mL of water at 27°C is _________ Pa. [Integer value]
(use R = 0.083 L bar mol–1 K–1)

Given below are two statements:

Statement I: The esterification of carboxylic acid with an alcohol is a nucleophilic acyl substitution.

Statement II: Electron withdrawing groups in the carboxylic acid will increase the rate of esterification reaction.

Choose the most appropriate option