List of top Questions asked in JEE Main

Find correct order of acidic strength in the following reaction products \(P, Q, R \& S\):

Which of the following is the correct order with respect to the property indicated?

Select correct option :

For the reaction:
\[ Cl_2 + KOH \rightarrow KCl + KClO + H_2O \] 1 mole of Cl$_2$ is passed into 2 litre, 2 M KOH solution. Determine the molarity of Cl$^-$, ClO$^-$ and OH$^-$ respectively.

The wave number of three spectral line of H-atom are given. The correct set of spectral lines belonging to Balmer series?

Correct order of stability is :

Correct sequence of reagent for the given reaction:

. Number of different $\text{H}$-atoms in $(\text{Y})$

\(80\,\text{mL}\) of an organic compound is mixed with \(264\,\text{mL}\) of \(O_2\) and ignited. It gives \(224\,\text{mL}\) of gaseous mixture at NTP. After passing through KOH, \(64\,\text{mL}\) of gas remains. The organic compound is:

‘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:

A compound ‘A’ with molecular formula \( \text{C}_9\text{H}_{11}\text{NO} \) reacts with \( \text{Br}_2/\text{NaOH} \) to give \( (X) \). On reaction with \( \text{NaNO}_2 \) in dilute HCl, it gives compound \( (Y) \). When \( (Y) \) is treated with CuCN, followed by hydrolysis, it gives \( (Z) \). The compound \( (A) \) on hydrolysis also gives compound \( (Z) \). Identify compound \( (A) \).

A gas undergoes a process in which state variable changes from (1 atm, 60 mL, 27°C) to (P atm, 30 mL, 77°C). Then, \( P \) is

Select the correct match between List-I and List-II:
List-I:
(I) Isothermal reversible (1 mole ideal gas, T = 300K, 2dm$^3$ to 20dm$^3$) calculate $|w|$
(II) Isothermal irreversible [3KPa, 1m$^3$ to 3m$^3$] calculate $|w|$
(III) 1 mole gas undergoes constant pressure process in which change in temperature is 400K, C$_p$ = 5R/2, $\Delta H$ will be
(IV) 1 mole ideal gas having C$_v$ = 3R/2 and $\Delta T$ = 320K, calculate $\Delta U$
List-II:
(A) 8.32
(B) 6
(C) 4
(D) 5.74

In Carius method of estimation of ‘Br’, 1.53 g of an organic compound gave 1 g AgBr. The % of Br in the organic compound is: (Atomic mass of Ag, Br = 108, 80 u respectively)

Match isostructural species in Column I with Column II.

The correct bond angle in the compound which has maximum number of lone pair of electrons among the following compounds H$_2$SO$_4$, HNO$_3$, O$_3$, NF$_3$ is:

Which of the following reaction is correctly matched with their product ?

Statement–I: Sucrose is dextrorotatory and upon hydrolysis it becomes laevorotatory. Statement–II: Sucrose on hydrolysis gives glucose and fructose such that the laevorotation of glucose is more than the dextrorotation of fructose. Choose the correct option.

Correct order of acidic strength: (I) Phenol, (II) p-Cresol, (III) m-Nitrophenol, (IV) p-Nitrophenol

Given below are two statements: Statement–I: $K_H$ is constant with change in concentration of gas till the solution is dilute at a given temperature. Statement–II: According to Henry’s law, the partial pressure of gas in vapour phase is inversely proportional to the mole fraction of gas in solution.

Observe the following reaction sequence:
\text{(P) }\xrightarrow{\text{NH}_3, \Delta} \text{(Q)} \xrightarrow{\text{Br}_2, \text{KOH}} \text{(R)}
Which of the following is the correct structure for P, Q, and R?