Q. In the reaction BrO₃⁻(aq) + 5Br⁻(aq) + 6H⁺(aq) → 3Br₂(l) + 3H₂O(l), the rate of appearance of bromine (Br₂) is related to rate of disappearance of bromide ions as following:
A) d[Br₂]/dt = −(5/3) d[Br⁻]/dt
B) d[Br₂]/dt = (5/3) d[Br⁻]/dt
C) d[Br₂]/dt = (3/5) d[Br⁻]/dt
D) d[Br₂]/dt = −(3/5) d[Br⁻]/dt
Explanation
[Solution from source] Rate = (1/3)d[Br₂]/dt = −(1/5)d[Br⁻]/dt, so d[Br₂]/dt = −(3/5)d[Br⁻]/dt. The minus sign is needed because [Br⁻] decreases while [Br₂] increases, and 5/3 inverts the stoichiometric ratio. Answer (4).
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.