List of top Chemistry Questions asked in JEE Main

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
Amongst the following, the number of oxide(s) which are paramagnetic in nature is
Na2O, KO2, NO2, N2O, ClO2, NO, SO2, Cl2O
Number of complexes which will exhibit synergic bonding amongst, \([Cr(CO)_6]\), \([Mn(CO)_5]\) and \([Mn_2(CO)_{10}]\) is ________.
Some gases are responsible for heating of atmosphere (green house effect). Identify from the following the gaseous species which does not cause it.
\(PCl_5\) 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)
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
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)
Consider the following reaction: 
A + alkali → B (Major Product)
If B is an oxoacid of phosphorus with no P-H bond, then A is
The products obtained during treatment of hard water using Clark’s method are:
What will be the major product of the following sequence of reactions?
\(n−Bu−≡ \xrightarrow[{(ii)Lindlar catalyst, H_2}]{(i)n-BuLi,n-C_5H_{11}Cl}\)
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.
Dinitrogen and dioxygen, the main constituents of air do not react with each other in atmosphere to form oxides of nitrogen because

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:

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 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 _____.

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)
(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______.

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

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. One is labelled as Assertion A and the other is labelled as Reason R.
Assertion A: Activated charcoal adsorbs \(SO_2\) more efficiently than \(CH_4\).
Reason R: Gases with lower critical temperatures are readily adsorbed by activated charcoal.
In the light of the above statements, choose the correct answer from the options given below.
Sulphur dioxide is one of the components of polluted air. SO2 is also a major contributor to acid rain. The correct and complete reaction to represent acid rain caused by SO2 is

In the given reaction

In the given reaction ‘A’ can be

 ‘A’ can be