pub const WATER_VAPOUR_MOLECULAR_WEIGHT_KG_PER_KMOL: f64 = 18.015_28;Expand description
Molar mass of water vapour M_v, kg/kmol (A. Picard et al., “Revised formula for the density
of moist air (CIPM-2007)”, Metrologia 45, 149–155 (2008), section 2.1).