释义 |
Gibbs phase rule
Gibbs phase rulen. Physics A rule stating that the number of degrees of freedom in a closed physical system at equilibrium is equal to the number of chemical components minus the number of phases plus the constant 2. For example, the system of water vapor, liquid water, and solid ice has zero degrees of freedom because the three phases of vapor, liquid, and solid coexist in the one component, water. Also called phase rule. [After Josiah Willard Gibbs.]Gibbs phase rule
Gibbs phase rule[′gibz ′fāz ‚rül] (physical chemistry) A relationship used to determine the number of state variables F, usually chosen from among temperature, pressure, and species composition in each phase, which must be specified to fix the thermodynamic state of a system in equilibrium: F = C-P-M +2, where C is the number of chemical species presented at equilibrium, P is the number of phases, and M is the number of independent chemical reactions. Also known as Gibbs rule; phase rule. MedicalSeephase rule |