JEE AdvancedHardQuestion 720015
Question
For the reaction 2NO₂ → 2NO + O₂ (second order in NO₂), if initial rate = 4×10⁻³ mol L⁻¹ s⁻¹ at [NO₂] = 0.1 M, then k is:
- A0.4 L mol⁻¹ s⁻¹Correct
- B4×10⁻² L mol⁻¹ s⁻¹
- C4×10⁻¹ L mol⁻¹ s⁻¹
- D4 L mol⁻¹ s⁻¹
Correct answer
0.4 L mol⁻¹ s⁻¹
Explanation
r = k[NO₂]². k = r/[NO₂]² = 4×10⁻³/(0.1)² = 4×10⁻³/10⁻² = 0.4 L mol⁻¹ s⁻¹.