Question

6. The Gibbs phase rule F = C - #P + 2 gives F, the number of degrees of freedom or the number of intensive variables (such as pressure, temperature, or mole fraction) that can be independently changed without disturbing the system's equilibrium state. The number of chemical species C is the minimum number needed to describe the composition of all the phases (number of substances minus the number of relations that constrain the amounts of the substances - in a) the amount of Na = the amount of Cl). For the following equilibrium systems identify what each component contributing to C and P is, determine F, and suggest reasonable independent intensive parameters. a) an aqueous solution of NaCl and KBr b) an aqueous solution of Na+, Cl“, K™, and Br c) a single gaseous phase of PC15, PC1z, and Cl, with the chemical reaction among these substances at equilibrium and each substance added separately d) same substances as in part c) but the system produced by starting only with PCI, e) an aqueous solution of acetic acid (CH3COOH) which is a weak acid which partially dissociates

Answer 1

@ Aq soln of Nach SK Br No. of corporet = 3 F = 3-1+2 P=1 (H2O, Nace, kBx) IF = 4 L 6 Aq soln of nat că , kit &.BE c'= 5-1=4 (420, Nat, ci, kt, B2) grestrichon=1 F = 4-1+2 (electroneutralita Ifa5 Pagt 4₂ (9) pels 9 P=1 C= 3-1=2 F=2 -1+2 TF=3 restonchions equilibrium condte.

- + Cl2 Coon Cuzcoot u 1 H₂O e=4- 1-1 reslichoni 2 - ے equilibriums electonical neutrality F = 2 - 1+2 [F=3