Determine the rate constant for each of the following first-order reactions:

(a) A → B + C, given that the concentration of A decreases to one-fourth its initial value in 125 min;

(b) 2 A → D + E, given that [A]₀ = 0.0421 mol · L^–1 and that after 63 s the concentration of D increases to 0.00132 mol · L^–1;

(c) 3 A → F + G, given that [A]₀ = 0.080 mol · L^–1 and that after 11.4 min the concentration of F rises to 0.015 mol · L^–1. In each case, write the rate law for the rate of loss of A.