Summary of the reactions studied in this work between ^•CH₃ + ^•CN on water and carbon monoxide ice surfaces. The first line indicates the possible outcomes of diffusive chemistry, while the second indicates the products after the reaction with one of the ice molecules from the surface. We note that after chemisorption, reaction products can proceed from two different mechanisms: chemisorption followed by H-abstraction (cyanic and isocyanic acid) or chemisorption followed by radical-radical coupling (acetimidic acid and acetyl cyanide).