9.2 Crystallization Flashcards
The driving potential for the crystal growth during crystallization is the ____________ of the solution
super-saturation
Crystallization is based on the ___________
Difference in solubility
During crystallization, formation of crystal can occur in ____________ solution only
supersaturated
How does temperature affect in nucleations
When Temperature (t) increases (^), nucleation decreases
Slow cooling maintaining a low level of super-saturation produces __________ crystals and fast cooling produces __________ crystals
Large , small
Slow cooling, ______ tempt , focus more on ______________
Higher temperature, crystal growth phase
Fast cooling, _______ tempt, focus more on what phase? Which produces
Lower tempt, nucleation, more crystals with small sizes
It’s the process by which crystalline bodies are created within a supersaturated fluid
Nucleation
What kind of operation is crystallization?
Mass and heat transfer
Facilitates crystalization
- hot concentrated solution is cooled for crystals to form
- solution is concentrated by evaporation
- adiabatic evaporation and cooling
The crystals and mother liquor obtained from a crystallizer are called __________
magma
Concentration of hydrogen peroxide is done by
Vacuum crystallization
Example of crystallization process
Purification of alum
Temperature favored
Crystal growth
Supersaturated favored
nucleation
High temp high solubility, concentration? And phase it favors?
Not so supersaturated, crystal growth
Crystallization of solids from a homogeneous solution is a/an ____ process
exothermic
When a solution is cooled to produce a supersaturated solution and hence to cause crystallization, the heat that must be removed is the sum of the ________________ necessary to cool the solution and the heat of crystallization
Sensible heat content
In most of the vacuum crystallizer, vacuum is generally produced by means of a
Steam jet ejector with a barometric condenser
