1
JEE Main 2026 (Online) 21st January Evening Shift
MCQ (Single Correct Answer)
+4
-1
Change Language

Decomposition of A is a first order reaction at T(K) and is given by  A(g) → B(g) + C(g).

In a closed 1 L vessel, 1 bar A(g) is allowed to decompose at T(K). After 100 minutes, the total pressure was 1.5 bar. What is the rate constant (in min−1) of the reaction? (log 2 = 0.3)

A

$6.9 × 10^{-4}$

B

$6.9 × 10^{-3}$

C

$6.9 × 10^{-1}$

D

$6.9 × 10^{-2}$

2
JEE Main 2026 (Online) 21st January Evening Shift
MCQ (Single Correct Answer)
+4
-1
Change Language

Given below are four compounds :

(a) n-propyl chloride       (b) iso-propyl chloride

(c) sec-butyl chloride      (d) neo-pentyl chloride

Percentage of carbon in the one which exhibits optical isomerism is :

A

46

B

40

C

52

D

56

3
JEE Main 2026 (Online) 21st January Evening Shift
MCQ (Single Correct Answer)
+4
-1
Change Language

The correct order of reactivity of the following benzyl halides towards reaction with KCN is :

JEE Main 2026 (Online) 21st January Evening Shift Chemistry - Haloalkanes and Haloarenes Question 16 English
A

a > b > c > d

B

b > a > d > c

C

b > a > c > d

D

a > b > d > c

4
JEE Main 2026 (Online) 21st January Evening Shift
MCQ (Single Correct Answer)
+4
-1
Change Language

Consider the following spectral lines for atomic hydrogen :

A. First line of Paschen series

B. Second line of Balmer series

C. Third line of Paschen series

D. Fourth line of Bracket series

The correct arrangement of the above lines in ascending order of energy is :

A

D < C < A < B

B

A < B < C < D

C

D < A < C < B

D

C < D < B < A

JEE Main Papers

All year-wise previous year question papers

2023
2021