The mechanism for the gas-phase reaction between H2 and Br2 is thought to be

Br2(g) 2Br(g) (rapid equilibrium)

H2(g) + Br(g) HBr(g) + H(g) (slow)

Br(g) + H(g) HBr(g) (fast).

What rate law is predicted by this mechanism when the rate-determining step approximation is used?

(The rate constant in the rate laws below is the effective rate constant.)

Group of answer choices

Rate = k[H2][Br2]

Rate = k[H2][Br2]

Rate = k[H2][Br2]

Rate = k[Br2]

Rate = k[H2]2[Br2]