MHT CET202523 Apr 2025Morning ShiftChemistryChemical KineticsActual
Find the rate of following reaction. 2 ~N ₂ O _ 5( ~g ) 4 NO _ 2( ~g ) + O _ 2( ~g ) if concentration of NO ₂ increases to 5.2 10⁻³ M in 100 seconds.
Options
- A1.3 10⁻³ ~mol dm ⁻³ ~s ⁻¹
- B1.3 10⁻⁵ ~mol dm ⁻³ ~s ⁻¹
- C4.0 10⁻⁵ ~mol dm ⁻³ ~s ⁻¹
- D5.2 10⁻⁵ ~mol dm ⁻³ ~s ⁻¹
Correct answer
B. 1.3 10⁻⁵ ~mol dm ⁻³ ~s ⁻¹
Step-by-step solution
The rate of formation of NO ₂ is determined from the concentration change and time interval as 5.2 10⁻³ M 100 s = 5.2 10⁻⁵ M/s . From the stoichiometry of the reaction 2 N₂O₅(g) 4 NO₂(g) + O₂(g) , the relationship between the reaction rate and the rate of NO₂ formation is Rate = 1 4 d[ NO₂ ] dt . Substituting gives Rate = 1 4 (5.2 10⁻⁵ M/s ) = 1.3 10⁻⁵ M/s . This matches option B : 1.3 10⁻⁵ mol~dm⁻³~s⁻¹ .