Worksheet: Crystallization
In this worksheet, we will practice describing the correct procedure for recrystallization and its use in the production of diffraction-quality crystals.
Q1:
Which of the following is not a method for increasing the crystallization rate?
- AGravity filtration
- BCooling the flask
- CAdding a second solvent
- DEvaporation of solvent
- EScratching the inside of the flask
Q2:
When performing a recrystallization, which of the following steps is not required?
- AThe solution is left to cool.
- BThe crude material is fully dissolved.
- CThe recrystallized material is washed.
- DThe hot solution is filtered.
- EThe unwanted solutions are disposed of safely.
Q3:
When applied to a solution, which of the following techniques could increase the purity of the resulting crystals?
- AScratching the inside of the flask
- BGravity filtration
- CEvaporation of solvent
- DAdding a seed crystal
- ECooling
Q4:
When recrystallizing a compound, for what purpose might the side of the flask be scratched with a glass rod?
- ATo accelerate secondary nucleation
- BTo mix the solution
- CTo accelerate the growth of existing crystals
- DTo accelerate primary nucleation
- ETo warm the solution
Q5:
Which of the following pieces of apparatus is not typically used in recrystallizations?
- A
- B
- C
- D
- E