List of top Chemistry Questions asked in JEE Main

Soluble in aqueous NaOH

Statement-1: Maltose is a non-reducing sugar.

Statement-2: Lactose is a reducing sugar.

Arrange the following groups according to their decreasing order of electron withdrawing nature – \( \text{COOH} \), \( \text{CN} \), \( I \), and \( \text{NO}_2 \).

Match the column-I with column-II:

Choose the correct match.

The reaction follows 1st order reaction \( \text{R} \rightarrow \text{P} \) Find the fraction of molecules dissociated in time \( t \). \([k_1 = \text{Rate constant}]\)

Anion \( X^- \) contains 45 neutrons and 36 electrons. The atomic mass, period number, and state in which "X" exists is:

An ideal gas is placed in a container at \( (P_1, V_1, T_1) \) and another ideal gas is placed in a different container at \( (P_2, V_2, T_2) \) are mixed at final pressure of \( P \) and final volume of \( V \). Calculate the final temperature.

Statement-1: Heat capacity at constant volume is always greater than heat capacity at constant pressure.
Statement-2: At constant volume as work done is zero, heat given to the chaotic motion is reflected by increase in temperature.

Consider the following reaction:

What is the colour of the final compound B?

Calculate the number of molecules and moles of \( \text{SO_2 \) in its 1.479 liters at STP.}

Match the column:

} Match correct reagents with given reactions:

For the reaction
\[ \text{A} + \text{B} \rightleftharpoons \text{C}, \quad K_p = 2.7 \times 10^{-5} \] Calculate \( K_p \) for the reaction
\[ \frac{1}{3} \text{A} + \frac{1}{3} \text{B} \rightleftharpoons \frac{1}{3} \text{C} \]

Statement-1: Under certain conditions, the covalency of oxygen can be up to 4. In \( \text{SO}_2 \), the oxidation state of oxygen is \( -2 \) and in \( \text{OF}_2 \), the oxidation state of oxygen is \( +2 \). Statement-2: The anomalous behaviour of oxygen in the 16th group is due to its small size and high electronegativity.

Choose the correct match.

(A) Bond angle Cr–O–Cr in \( \text{CrO}_7^{2-} \) is 126° (B) \( \text{Na}_2\text{Cr}_2\text{O}_7 \) is used as primary standard solution in titration. (C) \( \text{K}_2\text{Cr}_2\text{O}_7 \) oxidises \( \text{Fe}^{2+} \) into \( \text{Fe}^{3+} \) in acidic medium. (D) \( \text{CrO}_4^{2-} \) and \( \text{Cr}_2\text{O}_7^{2-} \) are interconvertible by changing pH.

For process \( X \to Y \), work done by the gas is 10 J and heat absorbed in the process is 2 J. For the reverse process, heat evolved is 6 J. Find the work done for the reverse process.

How many of the following are paramagnetic:
Lu\(^{3+}\), Yb\(^{2+}\), Gd\(^{2+}\), Ce\(^{4+}\), La\(^{3+}\), Zn\(^{2+}\), Cu\(^{2+}\), Mn\(^{2+}\), Sc\(^{3+}\), and Ti\(^{4+}\)

Identify correct statement(s):
(i) \( \text{Ar–Cl} \) and \( \text{R–Cl} \) show similar chemical properties.
(ii) Rate of \( S_N^1 \) \( C_6H_5CH_2–Cl<C_6H_5–CH–C_6H_5 \)
(iii) Alcohol is more polar than water, so alcoholic KOH shows elimination reaction.
(iv) Vinyl alcohol is an alkene, whereas allyl alcohol is an alkyne.
(v) Alcohol with SOC\(_2\) gives alkyl halide, but phenol does not give.

"X" is an oxoanion of the lightest element of group 7 (in the periodic table). The metal is in +6 oxidation state in "X". The color of the potassium salt of X is

Given below are two statements: Statement I: Glucose is found to exist in two different anomeric forms \(\alpha\) and \(\beta\). Statement II: In open chain structure, \(C_2, C_3, C_4\) of glucose and fructose both have same orientation. In light of above statements choose the correct option.

Given below are two statements: Statement I: The shape of \(ICl_3^{-}\) is square planar. Statement II: The shape of \(ClBr_2^{-}\) is pyramidal. In light of above statements choose the correct option.

Consider the following electrochemical cell \[ Zn | Zn^{2+}(aq) \, || \, Ag^{+}(aq) | Ag \] \[ [Zn^{2+}] = 1\,M \] The \(E_{cell\) was found to be \(1.6\,V\). The value of \(\log[Ag^+]\) is \[ E^\circ_{Zn^{2+}/Zn} = -0.76\,V , \qquad E^\circ_{Ag^+/Ag} = +0.80\,V \]

Which compound has total molecular mass of 72 with three primary carbons?

Consider the following equilibrium: \[ 2AB \rightleftharpoons A_2 + B_2 \] If equilibrium pressure is \(P\) and degree of dissociation is \(\alpha\), then \(K_p\) is