We have applied the CCSD(T)-F12a/cc-pVTZ-F12//CCSD(T)/cc-pVTZ level of theory to calculate energies for 22 reactions pertinent to the stability and reactivity of hardly isolable cyanoform (HC(CN)(3)). A number of exothermic processes has been indicated, especially the hydration. In the predicted mechanism for the gas-phase hydration of cyanoform, the H2O addition to the C.N bond corresponds to a rate-limiting step, which is aided by an extra molecule of water. Also, for the cyanoform dihydrate (H2NC(OH)C(CN)CONH2) product, the experimentally identified compound, the more stable planar isomer exhibits intramolecular O-H center dot center dot center dot O C (not N-H center dot center dot center dot O.C) H-bonding. Our calculated structures, binding energies, and NBO data for [HC(CN)(3)](n) (n = 2,4) clusters suggest that the nonconventional C-H center dot center dot center dot N H-bonds contribute to their stability. Among the surveyed structures of the C N group incorporating products of reactions examined, the CCSD(T)/cc-pVTZ molecular parameters of cyanocarbons C-2(CN)(4), C-2(CN)(6), and C-6(CN)(6) can be regarded as the most accurate gas-phase values up-to-date.