MHT CET202520 Apr 2025Morning ShiftChemistryChemical KineticsActual
Which of the following equations is correct regarding rate of disappearance of reactant and appearance of product for N _ 2(g) +3 H _ 2(g) 2 NH _ 3(g)
Options
- A3 ~d [ ~N ₂ ] dt = 1 2 ~d [ ~N ₂ ] dt
- B1 2 ~d [ ~N ₂ ] dt = 1 3 ~d [ H ₂ ] dt
- C2 ~d [ NH ₃ ] dt =3 ~d [ H ₂ ] dt
- D3 ~d [ NH ₃ ] dt =-2 ~d [ H ₂ ] dt
Correct answer
D. 3 ~d [ NH ₃ ] dt =-2 ~d [ H ₂ ] dt
Step-by-step solution
The balanced chemical equation is: N _ 2(g) + 3 H _ 2(g) 2 NH _ 3(g) . The general form for reaction rate is expressed as Rate = - 1 a d[A] dt = - 1 b d[B] dt = + 1 c d[C] dt = + 1 d d[D] dt , which gives for this reaction Rate = - d[ N ₂] dt = - 1 3 d[ H ₂] dt = + 1 2 d[ NH ₃] dt . Relating the disappearance of H ₂ to the appearance of NH ₃ : - 1 3 d[ H ₂] dt = + 1 2 d[ NH ₃] dt . Multiplying both sides by 6 to eliminate denominators: -2 d[ H ₂] dt = 3 d[ NH ₃] dt . Rearranged, this yields 3 d[ NH ₃] dt = -2 d[ H