Chapter 7 One-component Phase Equilibrium
1 Chapter 7 One-component Phase Equilibrium
Physical Chemistry Chapter 7 The phase rule Phase: a state of matter that is uniform throughout in chemical composition and physical state. ( Gibbs) Number of phase(p) e Gas or gaseous mixture -single phase Liquid -one, two and three phases two tally miscible liquids- single phase a slurry of ice and water -two phases Solid -a crystal is a single phase an alloy of two metals-two phases(immiscible) one phase(miscible
2 The Phase Rule Phase: a state of matter that is uniform throughout in chemical composition and physical state. (Gibbs) Number of phase (p): Gas or gaseous mixture – single phase Liquid – one, two and three phases two tally miscible liquids – single phase a slurry of ice and water – two phases Solid – a crystal is a single phase an alloy of two metals – two phases (immiscible) - one phase (miscible) Physical Chemistry Chapter 7
Physical Chemistry Chapter 7 The phase rule The difference between(a)a single-phase solution, in which the composition is uniform on a microscopic scale, and(b)a dispersion, in which regions of one component are embedded in a matrix of a second component
3 The Phase Rule (a) (b) The difference between (a) a single-phase solution, in which the composition is uniform on a microscopic scale, and (b) a dispersion, in which regions of one component are embedded in a matrix of a second component. Physical Chemistry Chapter 7
Physical Chemistry Chapter 7 The phase rule The difference between(a) constituent and(b) component constituent: a chemical species(an ion or a molecule that is present in a system component: a chemically independent constituent of a system number of components(c: the minimum number of independent species necessary to define the composition of all the phase present in the system
4 The Phase Rule The difference between (a) constituent and (b) component constituent: a chemical species (an ion or a molecule) that is present in a system component: a chemically independent constituent of a system number of components (c): the minimum number of independent species necessary to define the composition of all the phase present in the system Physical Chemistry Chapter 7
Physical Chemistry Chapter 7 The phase rule When no reaction takes place, The number of constituent= the number of component Pure water: a one-component system water Mixture of ethanol and a two-component system water: ethanol water
5 The Phase Rule When no reaction takes place, The number of constituent = the number of component Pure water: a one-component system Mixture of ethanol and water: a two-component system water ethanol water Physical Chemistry Chapter 7