List of top Chemistry Questions asked in JEE Main

When a nitro group is attached to a benzene ring, what effect do we observe towards reactions:

[(I)] Deactivating towards electrophilic substitution
[(II)] Activating towards electrophilic substitution
[(III)] Deactivating towards nucleophilic substitution
[(IV)] Activating towards nucleophilic substitution
Find the correct statements:
‘X’ \(\xrightarrow[(2)\ \mathrm{H_2O}]{(1)\ \mathrm{NaNO_2/HCl}}\) \(\xrightarrow[\ ]{\mathrm{NaOH/I_2}}\) ‘Y’ (gives positive iodoform test):
X has \(%C = 65.75%\), \(%H = 15.25%\), \(%N = 19%\).
Identify ‘X’ among the following:
Observe the following reaction sequence:
\[ \text{C}_4\text{H}_8 \xrightarrow{\text{HCl}} \text{C}_4\text{H}_7\text{Cl} \xrightarrow{\text{NH}_3} \text{C}_4\text{H}_9\text{NH}_2 \xrightarrow{\text{NaNO}_2 + \text{HCl}} \text{C}_4\text{H}_9\text{OH} \] Which of the following is the correct structure for A, B, and C?
Which pair among the following compounds have equal number of hyperconjugation:
Given the reaction sequence:
The percentage of Nitrogen in compound E is:
Compare rate of nitration in decreasing order:
In ‘S’ estimation, \(0.314\,\text{g}\) of an organic compound gave \(0.4813\,\text{g}\) of barium sulphate. What is the percentage (%) of sulphur in the organic compound? (Report to nearest integer)
Which of the following reactions yield alcohol as the major product:
(X) \(\text{NH}_3\), \(\Delta\) \(\longrightarrow\) (A)
(i) KOH + Br$_2$
(ii) CHCl$_3$, NaOH
X will be:
All possible isomers of C$_3$H$_7$Br when reacted with aq. KOH. Find out total number of optically active products (without rearrangement).

Select the correct statement regarding compounds P, Q, R, S. 
Structures: P = Acetophenone, Q = Phenylacetaldehyde, R = Cinnamyl alcohol, S = Acetophenone. 

 

Which of the following are {insoluble in alkali} when reacted with Hinsberg reagent?
Find correct order of acidic strength in the following reaction products \(P, Q, R \& S\):
Aniline (9.3 g) on reaction with acetic anhydride forms X (11 g). Find the percentage yield of the reaction.
Statement (A): Resonating structure with more $\sigma$-bonds charges far apart are more stable.
Statement (B): Unsaturated hydrocarbon shows +I or –I depending upon the group they are attached with.
Statement (C): Carbanion with more % s character are more stable.
Statement (D): In nucleophilic addition to carbonyl group –E (electron-withdrawing) effect is responsible while in electrophilic additions +E is responsible.
Statement (E): Alkene having more alkyl groups have more heat of hydrogenation.
How many statements are correct?
Statement-I : $\text{CH}_2=\text{CH}-\text{Cl}$ is having stronger $\text{C}-\text{Cl}$ bond then $\text{CH}_3-\text{CH}_2-\text{Cl}$.
Statement-II : $\text{Ph}-\text{C}(\text{Et})(\text{Me})-\text{Cl}$ will rotate the plane polarised light after solvation.
An organic compound contains C, H and O. 0.25 g of organic compound on combustion produces CO$_2$(g) and H$_2$O(l). When residual gases pass through KOH solution, its mass increases by 0.18 g and when passed through anhydrous CaCl$_2$, the increase in mass of CaCl$_2$ is 0.15 g. Find the mass % of oxygen in the organic compound.
Statement-I: RMgX reacts with CO$_2$ followed by acidification to form product, which reacts with NH$_3$/Δ and then reacts with NaOCl to form product which further reacts with CHCl$_3$/NaOH and final product is R–N≡C.
Statement-II: R–N≡C on hydrolysis gives RCOOH.
Consider the following reaction sequence:
The organic products ‘A’ and ‘B’ can be separated by:

Consider the following ions: 

\[ \text{(I)}\ \mathrm{CH_3-CH_2^-} \qquad \text{(II)}\ \mathrm{CH_2=CH^-} \qquad \text{(III)}\ \mathrm{HC \equiv C^-} \]

The stability of the ions is in the order:

$0.5 \text{ gm}$ of unknown organic compound undergo Duma's method for estimation of nitrogen. Percentage of nitrogen gas collected over water at $P = 715 \text{ mm}$ and $27^\circ \text{C}$ has volume $= 70 \text{ ml}$. Calculate $% \text{ N}$ in the unknown organic compound. ($\text{aq}$. $\text{Tension} = 15 \text{ mm}$)
The correct order of stability of given carbanions is:
An organic compound \(A\) with molecular formula \( \mathrm{C_4H_8O} \) gives a positive iodoform test and on oxidation forms a compound \(B\) which does not reduce Tollens' reagent. Identify compound \(A\).
Match the list-I and list-II name of reagent.
List-I (1) Baeyer's reagent
(2) Cerric Ammonium nitrate
(3) Tollen's reagent
(4) Neutral FeCl$_3$
List-II (P) Violet colour
(Q) Red
(R) Silver mirror
(S) Pink colour disappears
Correct sequence of reagent for the given reaction: