JEE Main 2026 · 4 Apr · Shift 2 · Chemistry Q74

ChemistryInteger+4 / -1Question 74 of 75

For a first order reaction $\ce{A -> B}$

$x$ = ________ min. (Nearest integer)

Your answer

Answer and worked solution

Official answer: 7

First order. From 0.65 to 0.00065 M is a factor $10^3$ in 20 min, so each tenfold fall takes $\frac{20}3$ min.

x. 0.65 → 0.065 is one tenfold fall: $x=6.67\approx7$ min.

Answer: 7

JEE Main 2026 · 4 Apr · Shift 2, Chemistry question 74