reaction enthalpy number [rē`ak·shǝn `en´thal·pē ´nǝm·bǝr] PHYSICAL CHEMISTRY A dimensionless number used in the study of interphase transfer in chemical reactions, equal to the enthalpy of reaction per unit mass of a specified compound produced in a reaction, times the mass fraction of that compound, divided by the product of the specific heat at constant pressure and the temperature change during the reaction. |