List of top Chemistry Questions on reaction mechanism asked in JEE Main

Given below are two statements:
Statement I: Phenol on treatment with $ \mathrm{CHCl_3/aq.\ KOH} $ under refluxing condition, followed by acidification produces p-hydroxy benzaldehyde as the major product and o-hydroxy benzaldehyde as the minor product.
Statement II: The mixture of p-hydroxybenzaldehyde and o-hydroxybenzaldehyde can be easily separated through steam distillation.
In the light of the above statements, choose the correct answer from the options given below

Given below are two statements:
Statement I: The dipole moment of R–CN is greater than R–NC and R–NC can undergo hydrolysis under acidic medium to produce R–COOH.
Statement II: R–CN hydrolyses under acidic medium to produce a compound which on treatment with SOCl$_2$, followed by the addition of NH$_3$ gives another compound (X). This compound (X) on treatment with NaOCl/NaOH gives a product, that on treatment with CHCl$_3$/KOH/$\Delta$ produces R–NC.
In the light of the above statements, choose the correct answer from the options given below.

The correct order of the rate of reaction of the following reactants with nucleophile by $ \mathrm{S_N1} $ mechanism is:
(Given: Structures I and II are rigid)

Which reagent gives bright red ppt. With $Ni^{2+}$ in basic medium?

Best reducing agent among the given ions are:

Match the following:

	LIST I		LIST II
A	Lyman	I	Near IR
B	Balmer	II	Far IR
C	Paschen	III	Visible
D	p-fund	IV	UV

Find out the correct statement from the options given below for the above 2 reactions.

In the above reaction 'A' and 'B' are:

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

The reaction representing the Mond process for metal refining is _________.

Find out the major products from the following reaction sequence.

“A” obtained by Ostwald’s method involving air oxidation of$ NH_3$, upon further air oxidation produces “B”. “B” on hydration forms an oxoacid of Nitrogen along with evolution of “A”. The oxoacid also produces “A” and gives positive brown ring test.

For certain chemical reaction X 🡢 Y, the rate of formation of product is plotted against the time as shown in the figure. The number of correct statement/s from the following is______.
(A) Over all order of this reaction is one
(B) Order of this reaction can't be determined
(C) In region I and III, the reaction is of first and zero order respectively
(D) In region-II, the reaction is of first order
(E) In region-II, the order of reaction is in the range of 0.1 to 0.9.

Following chromatogram was developed by adsorption of compound 'A' on a 6 cm TLC glass plate. Retardation factor of the compound 'A' is_____ $\times 10^{–1}$.

20 mL of 0.1 M NH₄OH is mixed with 40 mL of 0.05 M HCl.The pH of the mixture is nearest to(Given :K_b(NH₄OH) = 1×10^–5,log2 = 0.30,log3 = 0.48, log5 = 0.69,log7 = 0.84,log11 = 1.04)

The reagent, from the following, which converts benzoic acid to benzaldehyde in one step is

The increasing order of nucleophilicity of the following nucleophiles is : (a) ${CH_3CO^{\ominus}_2}$ (b) ${H_2O} $ (c) ${CH_3SO^{\ominus}_3}$ (d) ${O^{\ominus}H}$