WorksheetsCrystallization - Part 1
Total questions: 10
Worksheet time: 5mins
Crystallization is best described as:
Formation of solids by chemical reaction in gases
Precipitation of a solute from a liquid mixture to form solid crystals
Dissolution of a solid in a liquid solvent
Separation of vapor and liquid phases
Which of the following steps occurs first in the crystallization process?
Crystal growth
Washing of crystals
Supersaturation
Filtration
In the Ostwald–Miers diagram, the region where spontaneous nucleation occurs is called the:
Stable zone
Metastable zone
Unstable (labile) zone
Saturated zone
Supersaturation can be achieved by:
Cooling the solution
Evaporating the solvent
Adding an antisolvent
All of the above
Homogeneous nucleation occurs when:
Foreign particles act as nucleation sites
Nuclei form spontaneously in the pure solution
Seed crystals are added intentionally
Agitation rate is high
Which statement about crystal growth is correct?
Growth occurs only in pure solvents
Growth involves both mass transport and surface attachment
Growth rate is independent of supersaturation
Growth is only controlled by agitation speed
Crystal habit refers to:
The purity of the crystal
The rate of crystal nucleation
The external shape and proportions of a crystal
The molecular weight of the solute
In crystallization, impurities generally:
Enhance crystal growth in all directions
Inhibit crystal growth and affect morphology
Have no effect on the process
Always dissolve completely
The solubility of KNO3 increases rapidly with temperature. Therefore, it is best crystallized by:
Evaporation
Cooling
Reaction
Centrifugation
The main advantage of continuous crystallizers like the DTB or Oslo type is:
Small production scale
Uncontrolled supersaturation
Continuous operation and steady product quality
No need for agitation
