MHT CET202617 April 2026Evening ShiftChemistryChemical KineticsActual
Which of the following is an example of second order reaction ?
Options
- A2 , H ₂ O _ 2(l) 2 H ₂ O _ (l) + O _ 2(g)
- BCH ₃ CHO _ (g) CH _ 4(g) + CO _ (g)
- C2 , NO _ 2(g) + F _ 2(g) 2 NO ₂ F _ (g)
- D2 , NO _ (g) + 2 H _ 2(g) N _ 2(g) + 2 H ₂ O _ (l)
Correct answer
C. 2 , NO _ 2(g) + F _ 2(g) 2 NO ₂ F _ (g)
Step-by-step solution
The order of a reaction is determined experimentally by its rate law. For the decomposition of hydrogen peroxide, the rate law is Rate = k[ H ₂ O ₂] . It is a first-order reaction. For the thermal decomposition of acetaldehyde, the rate law is Rate = k[ CH ₃ CHO ]^ 1.5 . It is a fractional-order (1.5) reaction. For the reaction between NO ₂ and F ₂ , the mechanism involves a slow rate-determining step: NO ₂ + F ₂ NO ₂ F + F . The rate law is Rate = k[ NO ₂][ F ₂] . The overall order is 1 + 1 = 2 , making it a secon