e_aq⁻ half-life at k_eff=1: t_½ = log(2); concentration halves exactly

Sympy-exact witness of the pseudo-first-order half-life identity on the hydrated electron. Setup: [e_aq⁻](t) = e₀·exp(−k_eff·t) where k_eff = k[S]; half-life is the time at which concentration halves. Symbolically: t_½ = log(2)/k_eff. …