HALOGENATION OF PROPANONE

Review

Overall Reaction	Pk + I2 → PI + H+ + I-
Proposed Mechanism
Overall Rate of Consumption of Iodine	-d[I2]/dt = + k2[Pe][I2]
Steady State Approximation	d[Pe]/dt = 0
Overall Rate of Production of Pe	d[Pe]/dt = + k1[H+][Pk] - k-1[Pe][H+] - k2[Pe][I2]

Steady State Concentration of the enol form of Propanone {[P_e]_ss}

Applying the Steady State Approximation to the overall rate of production of the enol form of proponone, gives

0 = + k₁[H⁺][P_k] - k_-1[P_e][H⁺] - k₂[P_e][I₂]

On rearrangement, the steady state concentration of the enol form of propanone is found to be

[P_e]_ss = + k₁[H⁺][P_k] / (k_-1[H⁺] + k₂[I₂])

[P_e]_ss = - k₁[H⁺][P_k] / (k_-1[P_e][H⁺] - k₂[P_e][I₂])

[P_e]_ss = + k₁[H⁺][P_k] / (k_-1[H⁺] - k₂[I₂])

[P_e]_ss = - k₁[H⁺][P_k] / (k_-1[H⁺] + k₂[I₂])