List of top Chemistry Questions on Organic Chemistry asked in JEE Main

Consider the following reactions: 

The oxidation states of Cu in Z and Q, respectively are:

A student performed analysis of aliphatic organic compound 'X' which on analysis gave C = 61.01%, H = 15.25%, N = 23.74%. This compound, on treatment with HNO\(_2\)/H\(_2\)O produced another compound 'Y' which did not contain any nitrogen atom. However, the compound 'Y' upon controlled oxidation produced another compound 'Z' that responded to iodoform test. The structure of 'X' is:
Total number of alkali insoluble solid sulphonamides obtained by reaction of given amines with Hinsberg's reagent is: Amines: Aniline, N-Methylaniline, Methanamine, N,N-Dimethylmethanamine, N-Methyl methanamine, Phenylmethanamine, N-propylaniline, N-phenylaniline, N,N-Dimethylaniline, Allyl amine, Isopropyl amine
The number of isoelectronic species among S2−, C4−, Mn2+, Co3+ and Fe3+ is ‘n’.

If ‘n’ moles of AgCl is formed during the reaction of the complex with formula
CoCl2(en)2NH3
with excess AgNO3 solution, then the number of electrons present in the t2g orbital of the complex is ________.
For the given reaction:
CaCO3 + 2HCl → CaCl2 + H2O + CO2

If 90 g CaCO3 is added to 300 mL of HCl which contains 38.55% HCl by mass and has density 1.13 g mL-1,
then which of the following option is correct?

Given molar mass of H, Cl, Ca and O are 1, 35.5, 40 and 16 g mol-1 respectively.

Which of the following reaction is NOT correctly represented? 

Consider the following two first-order reactions: A \(\to\) B (first reaction) C \(\to\) D (second reaction) The rate constant for first reaction at 500 K is double of the same at 300 K. At 500 K, 50% of the reaction becomes complete in 2 hours. The activation energy of the second reaction is half of that of first reaction. If the rate constant at 500 K of the second reaction becomes double of the rate constant of first reaction at the same temperature; then rate constant for the second reaction at 300 K is ______ \(\times 10^{-3}\,\text{hour}^{-1}\) (nearest integer).
A student has been given 0.314 g of an organic compound and asked to estimate Sulphur. During the experiment, the student has obtained 0.4813 g of barium sulphate. The percentage of sulphur present in the compound is ________. (Given Molar mass in g mol$^{-1}$: S, 32; BaSO$_4$, 233)
The reactions which produce alcohol as the product are :

The correct order of acidic strength of the major products formed in the given reactions is: 

Given below are two statements: Statement I: Griess–Ilosvay test is used for the detection of nitrite ion, which involves the use of sulphanilic acid and \(\alpha\)-naphthylamine reagent. Statement II: In the above test, sulphanilic acid is diazotized by the acidified nitrite ion, which on further coupling with \(\alpha\)-naphthylamine forms an azo-dye. In the light of the above statements, choose the correct answer from the options given below.

Consider the following reaction sequence: 

Given: Compound (x) has percentage composition \(76.6%\ \text{C}\), \(6.38%\ \text{H}\) and vapour density \(=47\). Compound (y) develops a characteristic colour with neutral \(\mathrm{FeCl_3}\) solution. Identify the {INCORRECT statement.}

\(0.53\ \text{g}\) of an organic compound \(X\) when heated with excess concentrated nitric acid and then with silver nitrate gave \(0.75\ \text{g}\) of silver bromide precipitate. \(1.0\ \text{g}\) of \(X\) gave \(1.32\ \text{g}\) of \(\mathrm{CO_2}\) on combustion. Find the percentage of hydrogen in compound \(X\). (Nearest integer) [Given: Atomic masses (g mol\(^{-1}\)): H = 1, C = 12, Br = 80, Ag = 108, O = 16]
Given below are two statements: Statement I: The number of pairs, from the following, in which {both the ions are coloured} are \([\text{Sc}^{3+},\text{Ti}^{3+}]\), \([\text{Mn}^{2+},\text{Cr}^{2+}]\), \([\text{Cu}^{2+},\text{Zn}^{2+}]\) and \([\text{Ni}^{2+},\text{Ti}^{4+}]\). Statement II: \(\text{Ti}^{4+}\) is the strongest reducing agent among \(\text{Th}^{4+}, \text{Ce}^{4+}, \text{Gd}^{3+}\) and \(\text{Eu}^{2+}\). In the light of the above statements, choose the correct answer.
Given below are two statements: Statement I: The number of species among \(\mathrm{BF_4^-}\), \(\mathrm{SiF_4}\), \(\mathrm{XeF_4}\) and \(\mathrm{SF_4}\), that have unequal E–F bond lengths is three. Here, E is the central atom. Statement II: Among \(\mathrm{O_2^-}\), \(\mathrm{O_2^{2-}}\), \(\mathrm{F_2}\) and \(\mathrm{O_2^+}\), \(\mathrm{O_2^+}\) has the highest bond order. In the light of the above statements, choose the correct answer.

Consider the following reactions giving major product. Identify the correct reaction. 

The correct order of stability for the following carbanions is: \[ \text{CH}_2=\text{CH}^- ,\quad \text{CH}_3-\text{CH}_2^- ,\quad \text{CH}\equiv\text{C}^- \]
Grignard reagent RMgBr (P) reacts with water and forms a gas (Q). One gram of Q occupies 1.4 dm$^3$ at STP. (P) on reaction with dry ice in dry ether followed by H$_3$O$^+$ forms compound (Z). 0.1 mole of (Z) will weigh _________ g (Nearest integer).
0.25 g of an organic compound “A” containing carbon, hydrogen and oxygen was analysed using combustion method. The increase in mass of CaCl$_2$ tube and potash tube at the end of the experiment was found to be 0.15 g and 0.1837 g respectively. The percentage of oxygen in compound A is ________ % (Nearest integer).
Find out the statements which are not true.
A. Resonating structures with more covalent bonds and less charge separation are more stable.
B. In electromeric effect, an unsaturated system shows +E effect with nucleophile and –E effect with electrophile.
C. Inductive effect is responsible for high melting point, boiling point and dipole moment of polar compounds.
D. The greater the number of alkyl groups attached to the doubly bonded carbon atoms, higher is the heat of hydrogenation.
E. Stability of carbanion increases with increase in s-character of the carbon carrying negative charge.
Given below are two statements:
Statement I: C–Cl bond is stronger in $\mathrm{CH_2 = CH{-}Cl}$ than in $\mathrm{CH_3{-}CH_2{-}Cl}$.
Statement II: The given optically active molecule, on hydrolysis, gives a solution that can rotate the plane polarized light.
In the light of the above statements, choose the correct answer from the options given below:
A hydroxy compound $(X)$ with molar mass $122\,\text{g mol}^{-1}$ is acetylated with acetic anhydride, using a large excess of the reagent ensuring complete acetylation of all hydroxyl groups. The product obtained has a molar mass of $290\,\text{g mol}^{-1}$. The number of hydroxyl groups present in compound $(X)$ is ___.
In Dumas method for estimation of nitrogen, 0.50 g of an organic compound gave 70 mL of nitrogen collected at 300 K and 715 mm pressure. The percentage of nitrogen in the organic compound is ____ %. (Aqueous tension at 300 K is 15 mm)

Consider the following two reactions A and B:

The numerical value of [molar mass of $x$ + molar mass of $y$] is ___. 
 

A student has been given a compound "x" of molecular formula- $C_6H_7N$. 'x' is sparingly soluble in water... On treatment with benzenesulphonyl chloride, 'x' gives a compound 'z' which is soluble in alkali. The number of different "H" atoms present in 'z' is:-