Phase Equilibria Flashcards
In separation processes, equilibrium is achieved by satisfying the ff conditions
Thermal Equilibrium
Mechanical Equilibrium
Chemical Potential Equilibrium
Phase rule is discovered by
J. Willard Gibbs
this relates the variance (degrees of freedom) F for a
nonchemically reactive system at heterogeneous
equilibrium to the number of coexisting phases P and
the number of components (chemical species) C
present
Phase rule
number of intensive
properties required to completely define the state of
the system
degrees of freedom, F
For a binary vapor-liquid mixture in equilibrium, F = ?
2
Useful in determining
phase states, phase-
transition temperatures,
phase compositions, and
phase amounts for a
given pressure.
T–x–y Diagram
Useful because the vapor
and liquid compositions
are points on the
equilibrium curve and
useful in geometric
constructions.
y–x Diagram
Mixture conditions above the saturated vapor curve
superheated vapor
conditions
below the saturated liquid curve
subcooled liquid
can be constructed to determine the equilibrium vapor and liquid compositions at a
temperature
Tie line
relative amounts of vapor and liquid phases are determined using
inverse lever arm rule
Azeotropic mixtures exhibit mainly _________ where the under isobaric
conditions, the azeotrope boils at a temperature lower than the boiling points of either of the two pure
components.
minimum-boiling azeotropes
shows an azeotrope boiling at a temperature greater
than the boiling points of either of the two pure components
maximum-boiling azeotropes
The curve within the diagram is called ______ which are determined by a ______
miscibility limits
cloud-point titration
Any point inside the miscibility limit is a ______ mixture while outside of it is a ____ mixture.
two-phase
One-phase
where the tie lines converge, the
to liquid phases have identical compositions.
plait point
𝑚𝑖𝑥𝑡𝑢𝑟𝑒 𝑜𝑓 𝑡𝑤𝑜 𝑜𝑟 𝑚𝑜𝑟𝑒 𝑙𝑖𝑞𝑢𝑖𝑑𝑠
𝑤ℎ𝑜𝑠𝑒 𝑝𝑟𝑜𝑝𝑜𝑟𝑡𝑖𝑜𝑛𝑠 𝑐𝑎𝑛𝑛𝑜𝑡 𝑏𝑒 𝑎𝑙𝑡𝑒𝑟𝑒𝑑 𝑏𝑦 𝑠𝑖𝑚𝑝𝑙𝑒 𝑑𝑖𝑠𝑡𝑖𝑙𝑙𝑎𝑡𝑖𝑜𝑛
Azeotropic mixture
𝒘𝒉𝒂𝒕 𝒊𝒔 𝒕𝒉𝒆 𝒅𝒆𝒈𝒓𝒆𝒆𝒔 𝒐𝒇 𝒇𝒓𝒆𝒆𝒅𝒐𝒎 𝒐𝒇 𝒂𝒏 𝒂𝒛𝒆𝒐𝒕𝒓𝒐𝒑𝒊𝒄 𝒎𝒊𝒙𝒕𝒖𝒓𝒆?
𝐹 = 2 − 2 + 2 − 1 = 1
𝑮𝒊𝒗𝒆𝒏 𝒂 𝒄𝒆𝒓𝒕𝒂𝒊𝒏 𝒕𝒆𝒎𝒑𝒆𝒓𝒂𝒕𝒖𝒓𝒆, 𝒘𝒉𝒂𝒕 𝒊𝒔 𝒕𝒉𝒆 𝒅𝒆𝒈𝒓𝒆𝒆𝒔 𝒐𝒇 𝒇𝒓𝒆𝒆𝒅𝒐𝒎 𝒐𝒇 𝒂𝒏 𝒂𝒛𝒆𝒐𝒕𝒓𝒐𝒑𝒊𝒄 𝒎𝒊𝒙𝒕𝒖𝒓𝒆
0
𝑾𝒉𝒂𝒕 𝒅𝒐𝒆𝒔 𝒕𝒉𝒆 𝒏𝒆𝒈𝒂𝒕𝒊𝒗𝒆 𝒔𝒍𝒐𝒑𝒆 𝒎𝒆𝒂𝒏𝒔 𝒊𝒏 𝒕𝒉𝒆 𝑷𝑻 𝒅𝒊𝒂𝒈𝒓𝒂𝒎 𝒐𝒇 𝒘𝒂𝒕𝒆𝒓?
𝑊𝑎𝑡𝑒𝑟 𝑒𝑥𝑝𝑎𝑛𝑑𝑠 𝑎𝑠 𝑖𝑡 𝑐ℎ𝑎𝑛𝑔𝑒𝑠 𝑓𝑟𝑜𝑚 𝑙𝑖𝑞𝑢𝑖𝑑 𝑠𝑡𝑎𝑡𝑒 𝑡𝑜 𝑠𝑜𝑙𝑖𝑑 𝑠𝑡𝑎𝑡𝑒, ℎ𝑒𝑛𝑐𝑒, 𝑖𝑐𝑒 𝑓𝑙𝑜𝑎𝑡𝑠 𝑖𝑛 𝑤𝑎𝑡𝑒𝑟. 𝐿𝑖𝑞𝑢𝑖𝑑 𝑤𝑎𝑡𝑒𝑟 𝑖𝑠 𝑑𝑒𝑛𝑠𝑒𝑟 𝑡ℎ𝑎𝑛 𝑠𝑜𝑙𝑖𝑑 𝑤𝑎𝑡𝑒𝑟.
