The formation of hydrogen bromide is proposed to occur by the following sequence:…
CHEMISTRY · Single correct · A Level · Chemistry · Rate equations · Rate equations
Problem
The formation of hydrogen bromide is proposed to occur by the following sequence:
Step 1 Br₂(g) ⇌ 2 Br(g) (fast, equilibrium)
Step 2 Br(g) + H₂(g) → HBr(g) + H(g) (slow)
Step 3 H(g) + Br₂(g) → HBr(g) + Br(g) (fast)
Which rate law is most consistent with this mechanism?
(a) rate=k[H2]1/2[Br2]
(b) rate=k[H2][Br2]1/2
(c) rate=k[H2][Br2]
(d) rate=k[Br2]1/2