List of top Chemistry Questions asked in JEE Main

Organic compound (X) + KOH $ \overset{H^+}{\rightarrow} $ gives product $ P $ having the same molar ratio of C : H : O. Identify product $ P $.

Which of the following are iso-structural with $ \text{SF}_4 $?

20 ml of 0.2 M HA ($ K_a = 5 \times 10^{-4} $) is titrated with 10 ml of 0.2 M NaOH solution. Calculate the initial and final value of pH of the solution. [Given $ \log 5 = 0.7 $]

Which of the following compounds shows coordination isomerism?
(A) $ [\text{Fe(NH}_3)_6] [\text{Co(CN)}_6] $
(B) $ [\text{Cr(NH}_3)_6] [\text{Co(CN)}_6] $
(C) $ [\text{Co(NH}_3)_6] [\text{Co(CN)}_6] $
(D) $ [\text{Ag(NH}_3)_2] [\text{Ag(CN)}_2] $
(E) $ [\text{Fe(NH}_3)_6] [\text{Cr(CN)}_6] $

Identify A and E

‘x’ be the osmotic pressure of a solution formed by dissolving 1g of a protein (M = 50,000 g/mol) in 0.5 litre and ‘y’ be the osmotic pressure of solution formed by dissolving 2g of the same protein in 1 litre at 300 K. If ‘z’ be the osmotic pressure of solution formed by mixing above two solutions. Then the value of ‘x’, ‘y’ and ‘z’ respectively are.
\text{Use: $ R = 0.083 \, \text{lit-bar/K-mol} $}

Molarity of $ H_2SO_4 (aq.) $ solution is 4.9 M. If the density of the solution is 1.40 g/mL, then molality and mole fraction of solute in the solution is:
(Molar mass of $ H_2SO_4 = 98 \, \text{g mol}^{-1} $)

Statement I:

The carbocation in the structure $ \text{O}_2\text{N}\text{C} \text{H} $ is stabilized by the +R effect of the $ \text{-OCH}_3 $ group.
Statement II:

The carbocation in the structure $ \text{O}_2\text{N}\text{C} \text{H} $ is stabilized by the +R effect of the $ \text{-NO}_2 $ group.

0.1 mole of $ H_2S $ is added in 1 liter of 0.1 HCl solution. Calculate the concentration of $ HS^{-} $.
[Given $ K_{a1} = 8.3 \times 10^{-8} $ and $ K_{a2} = 10^{-13} $]

What will be the mass of AgBr obtained when 1 gm of product is treated with AgNO₃ in the Carius method?

Match List I with List II.

Predict expression for $ \alpha $ in terms of $ K_{eq} $ and concentration
C: $ A_2B_3 \, (aq) \rightleftharpoons 2A^{3+} (aq) + 3B^{2-} (aq) $

Consider the following reaction sequence.

For the thermal decomposition of reactant AB(g), the following plot is constructed.

The half life of the reaction is 'x' min.
x =_______} min. (Nearest integer)}

From the following, the least stable structure is:
(Assume standard resonance structures)

Consider the following compounds. Arrange these compounds in a n increasing order of reactivity with nitrating mixture. The correct order is :

When $1$ g of compound $(X)$ is subjected to Kjeldahl's method for estimation of nitrogen, $15$ mL of $1$ M $\mathrm{H_2SO_4}$ was neutralized by ammonia evolved. The percentage of nitrogen in compound $(X)$ is:

Which of the following is most basic?

Consider the reaction given below:

$\text{A gives positive Fehling's test. Choose the correct relation}$.

Write the correct order of rate of reaction of following compounds with $PhN_2Cl$
P: $N,N$-dimethylaniline
Q: $N,N$-dimethyl-3-methylaniline
R: $N,N$-dimethyl-2,6-dimethylaniline

Identify (P)

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.

5.33 gram of $CrCl_3 \cdot 6H_2O$ (1:3 electrolyte) is passed through cation exchanger. The resulting solution is then treated with an excess of $AgNO_3$, leading to formation of 8.61 gran of precipitate. Calculate :
$\frac{\text{number of moles of complex reacted}}{\text{number of moles of AgCl precipitated}} \times 100$

Most preferred site for electrophilic substitution in above example?
(Note: The molecule contains a nitrogen-containing ring and a carbonyl-containing ring, labels are U, S, R, P).