JEE Main 2022 · 30 Jul · Shift 2 · Chemistry Q56

ChemistryInteger+4 / -1Question 56 of 90

X → Y + Z

X decomposes at 700 K to give Y and Z. The results of two measurements are :

Initial concentration of X / (mol/L)	6.0	12.0
Half life / s	1.0	2.0

The rate constant for the reaction is _______ (in appropriate unit)

Your answer

Answer and worked solution

Official answer: 3

Order. Half-life doubles when $[X]_0$ doubles, so the reaction is zero order and $t_{1/2}=\frac{[X]_0}{2k}$ .

Rate constant $k=\frac{6.0}{2\times1.0}=3$ mol L⁻¹ s⁻¹.

Answer: 3

JEE Main 2022 · 30 Jul · Shift 2, Chemistry question 56