List of top Chemistry Questions asked in JEE Main

The number of hyperconjugation structures involved to stabilize carbocation formed in the below reaction is _______

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

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 ____

The ratio x/y on completion of the above reaction is _____

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:

When a solution of mixture having two inorganic salts was treated with freshly prepared ferrous sulphate in acidic medium, a dark brown ferric ion was formed when treated with ferric chloride. It gave deep red colour which disappeared on boiling and a brown red ppt was formed. The mixture contains:

The polymer X consists of linear molecules and is closely packed. It is prepared in the presence of triethylaluminium and titanium tetrachloride under low pressure. The polymer X is:

For compound having the formula GaCl\(_3\), the correct option from the following is:

Which of the following complex has a possibility to exist as meridional isomer?

The value of x compound ‘D’ is

Three organic compounds A, B and C were allowed to run in thin layer chromatography using hexane and gave the following result (see figure). The R_f value of the most polar compound is ____ x 10^-2.

The reaction 2NO + Br2 → 2NOBr 
takes places through the mechanism given below : 
NO + Br2 ⇔ NOBr2 (fast)  
NOBr2 + NO → 2NOBr (slow) 
The overall order of the reaction is_____.

pH of 1 litre of HCL solution is 1. How much water (in litres) is added to make pH=2?

80 mole percent of MgCl₂ is dissociated in aqueous solution. The vapour pressure of 1.0 molal aqueous solution of M_gCl₂ at 38°C is ____mm Hg. (Nearest integer)
Given : Vapour pressure of water at 38°C is 50 mm Hg.

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 incorrect statement regarding the reaction given below is

The major products ‘P’ formed in the following sequence of reaction is

A in the above reaction is:

In the following reaction

A is

Products The two products formed in above reaction are

Correct statements for the given reaction are:

A. Compound 'B' is aromatic 
B. The completion of above reaction is very slow 
C. 'A' shows tautomerism 
D. The bond lengths C-C in compound B are found to be same 
Choose the correct answer from the options given below:

Match List-I with List-II

	List-I		List-II
A	Nitrogen oxides in air	I	Eutrophication
B	Methane in air	II	pH of rain water becomes 5.6
C	Carbon dioxide	III	Global warming
D	Phosphate fertilisers in water	IV	Acid rain

Choose the correct answer from the options given below:

Match List-I with List-II

	List-I-Complex		List-II-CFSE
A	[Cu(NH3​)6​]2+	I	-0.6
B	[Ti(H2​O)6​]3+	II	-2.0
C	[Fe(CN)6​]3−	III	-1.2
D	[NiF6​]4-	IV	-0.4

Choose the correct answer from the options given below:

Given below are two statement: one is labelled asAssertion A and the other is labelled as Reason R.
Assertion A: 5f electrons can participate in bonding to a far greater extent than 4f electrons 
Reason R: 5f orbitals are not as buried as 4f orbitals 
In the light of the above statements, choose the correct answer from the options given below: