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?
- ACooling the flask
- BEvaporation of solvent
- CGravity filtration
- DScratching the inside of the flask
- EAdding a second solvent
Q2:
When performing a recrystallization, which of the following steps is not required?
- AThe recrystallized material is washed.
- BThe crude material is fully dissolved.
- CThe solution is left to cool.
- 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?
- AGravity filtration
- BCooling
- CAdding a seed crystal
- DScratching the inside of the flask
- EEvaporation of solvent
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 accelerate the growth of existing crystals
- CTo warm the solution
- DTo mix the solution
- ETo accelerate primary nucleation
Q5:
Which of the following pieces of apparatus is not typically used in recrystallizations?
- A
- B
- C
- D
- E