Question

The reaction between hydrogen peroxide and iodide has been investigated by F. Bell, R. Gill, D. Holden, and W. F. K. Wynne-Jones in J. Phys. Chem. 55, 874 (1951): H₂O₂ + 2I^- + 2H⁺ ----> 2H₂O + I₂. The reaction proceeds by two parallel mechanisms and leads to the rate law:

-d[H₂O₂]/dt = d[I₂]/dt = k₁[H₂O₂][I^-] + k₂[H₂O₂][I^-][H⁺].

The rate constants k₁ and k₂ are observed to vary with ionic strength in the fashion shown in the table. Are these data qualitatively and quantitatively consistent with the primary salt effect in equation 5.35?

Equation 5.35: log₁₀k₀ = log₁₀k₀ +2Az_Az_BI_c^1/2

DATA TABLE:

Ic	k1 (M-1s-1)	k2 (M-2s-1)
0.000	0.658	19.0
0.0207	0.663	15.0
0.0525	0.670	12.2
0.0925	0.679	11.3
0.1575	0.694	9.7
0.2025	0.705	9.2

Answer 1