List of top Chemistry Questions asked in JEE Main

In the extraction process of copper, the product obtained after carrying out the reactions \[ \text{CuO} + \text{H}_2 \rightarrow \text{Cu} + \text{H}_2 \text{O} \] is called:
25 mL of silver nitrate solution (1M) is added dropwise to 25 mL of potassium iodide (1.05 M) solution. The ions(s) present in very small quantity in the solution is/are:
Given below are two statements:
Statement I: If BOD value is 4 ppm and dissolved oxygen is 8 ppm, it is a good quality water.
Statement II: If the concentration of zinc and nitrate is 5 ppm, then it can be used as good quality water.
In the above reaction 'A' and 'B' are:
A’ and ‘B’ in the above reactions are
The complex that dissolves in water is:
Solid fuel used in rocket is a mixture of Fe₂O₃ and Al (in ratio 1 : 2) the heat evolved (KJ) per gram of the mixture is ______ (Nearest integer)
Given \(\Delta H_f^{\circ}(Al_2O_3) = -1700 \, \text{KJ mol}^{-1}\)
\(\Delta H_f^{\circ}(Fe_2O_3) = -840 \, \text{KJ mol}^{-1}\) }
A mixture of 1 mole of H₂O and 1 mole of CO is taken in a 10 liter container and heated to 725 K. At equilibrium, 10 M of water by mass reacts with carbon monoxide according to the equation: \[ CO(g) + H_2O(g) \rightleftharpoons CO_2(g) + H_2(g) \] The equilibrium constant \( K_c \times 10^7 \) for the reaction is ______
An atomic substance A of molar mass 12 g mol$^{-1}$ has a cubic crystal structure with edge length of 300 pm. The no. of atoms present in one unit cell of A is _____ (Nearest integer)
The ratio x/y on completion of the above reaction is _____
ratio x/y on completion of
In an electrochemical reaction of lead, at standard temperature, if \( E^{\circ}(\text{Pb}^{2+}/\text{Pb}) = m \) volt and \( E^{\circ}(\text{Pb}^{4+}/\text{Pb}^{2+}) = n \) volt, then the value of \( E^{\circ}(\text{Pb}^{4+}/\text{Pb}) \) is given by \( m - xn \). The value of \( x \) is ____
A solution of sugar is obtained by mixing 200g of its 25% solution and 500g of its 40% solution (both by mass). The mass percentage of the resulting sugar solution is ______ (Nearest integer)
0.004 M K₂SO₄ solution is isotonic with 0.01 M glucose solution. Percentage dissociation of K₂SO₄ is______ (Nearest integer)
The number of hyperconjugation structures involved to stabilize carbocation formed in the below reaction is _______
hyperconjugation structures
The above reaction was studied at 300 K by monitoring the concentration of FeSO₄, in which initial concentration was 10 M and after half an hour became 8.8 M. The rate of production of Fe₂(SO₄)₃ is _____ × 10⁻⁶ mol L⁻¹ s⁻¹
Match List-I with List-II :

List I

(Reagents Used)

 

List II

(Compound with Functional group detected)

AAlkaline solution of copper sulphate and sodium citrateI
BNeutral FeCl3 solutionII
CAlkaline chloroform solutionIII
DPotassium iodide and sodium hypochloriteIV

Choose the correct answer from the options given below :

The mismatched combinations are
A. Chlorophyll - Co 
B. Water hardness - EDTA 
C. Photography - [Ag(CN)2]- 
D. Wilkinson catalyst - [(Ph3P)3 RhCl]  
E. Chelating ligand-D- Penicillamine
Given below are two statements, one is labelled as Assertion A and the other is labelled as Reason R.
Assertion A: [CoCl(NH3)]2– absorbs at lower wavelength of light with respect to [Co(NH3)5(H2O) 3–
Reason R: It is because the wavelength of the light absorbed depends on the oxidation state of the metal ion.
In the light of the above statements, choose the correct answer from the options given below:

What is the correct order of acidity of the protons marked A-D in the given compounds?
Acidity order

The density of the alkali metals is in the order:
The reaction representing the Mond process for metal refining is _________.
The standard electrode potential \((\frac{M^{3+}}{M^{2+}})\) for V, Cr, Mn & Co are –0.26 V, –0.41 V, +1.57 V and +1.97 V, respectively. The metal ions which can liberate H2 from a dilute acid are

For 1 mol of gas, the plot of pV vs. p is shown below. p is the pressure and V is the volume of the gas. What is the value of compressibility factor at point A?
Pv vs V graph

In Carius tube, an organic compound ‘X’ is treated with sodium peroxide to form a mineral acid ‘Y’. The solution of \(BaCl_2\), is added to ‘Y’ to form a precipitate ‘Z’. ‘Z’ is used for the quantitative estimation of an extra element. ‘X’ could be

The correct sequence of reagents for the preparation of Q and R is:
The correct sequence of reagents for the preparation of Q and R is:

Using column chromatography, mixture of two compounds ‘A’ and ‘B’ was separated. ‘A’ eluted first, this indicates ‘B’ has