Solubility and thermodynamics of solvation of krypton in aqueous-methanol solutions of urea at 101 325 Pa and 278–318 K: I. Effect of H/D isotope substitution

The solubility of Kr in H2O-CD3OH-CO(NH2)2 and D2O-CH3OD-CO(ND2)2 mixtures in the entire range of compositions of the mixed aqueous-methanol solvent at a urea content of up to 1.5 solvomolality units (mole fraction 0.0263) was measured at 101 325 Pa and 278.15–318.15 K (at 10 K step). The standard Sechenov parameters K S 0 of the solubility of Kr and the thermodynamic parameters of krypton-urea pair interactions were determined. A differentiating effect of the H/D isotope substitution on K S 0 was revealed: Upon deuteration of groups participating in strong hydrogen bonding, the Sechenov solubility parameter increases, and upon replacement of CH3 by CD3, decreases in the absolute value.