For any recrystallization, you should see the substance begin to dissolve when solvent is added
- at the moment when the solid just dissolves, the correct amount of solvent has been added.
Then, you may also observe some insoluble impurities (dust, etc). Or, some colored impurities
(naphthalene is colorless in solution) may be present. As you begin cooling the solution, crystals
may slowly begin to form, or you may have to cool the crystallizing solution further (with ice) to
induce crystallization. In some cases, you have to physically disturb to cooled mixture to get
crystals to form. In any case, these are filtered, and you may see some color left in the filtrate,
this indicates that some impurities have remained in solution. The pure crystals should be white.
Solution
For any recrystallization, you should see the substance begin to dissolve when solvent is added
- at the moment when the solid just dissolves, the correct amount of solvent has been added.
Then, you may also observe some insoluble impurities (dust, etc). Or, some colored impurities
(naphthalene is colorless in solution) may be present. As you begin cooling the solution, crystals
may slowly begin to form, or you may have to cool the crystallizing solution further (with ice) to
induce crystallization. In some cases, you have to physically disturb to cooled mixture to get
crystals to form. In any case, these are filtered, and you may see some color left in the filtrate,
this indicates that some impurities have remained in solution. The pure crystals should be white..
For any recrystallization, you should see the substance begin to dis.pdf
1. For any recrystallization, you should see the substance begin to dissolve when solvent is added
- at the moment when the solid just dissolves, the correct amount of solvent has been added.
Then, you may also observe some insoluble impurities (dust, etc). Or, some colored impurities
(naphthalene is colorless in solution) may be present. As you begin cooling the solution, crystals
may slowly begin to form, or you may have to cool the crystallizing solution further (with ice) to
induce crystallization. In some cases, you have to physically disturb to cooled mixture to get
crystals to form. In any case, these are filtered, and you may see some color left in the filtrate,
this indicates that some impurities have remained in solution. The pure crystals should be white.
Solution
For any recrystallization, you should see the substance begin to dissolve when solvent is added
- at the moment when the solid just dissolves, the correct amount of solvent has been added.
Then, you may also observe some insoluble impurities (dust, etc). Or, some colored impurities
(naphthalene is colorless in solution) may be present. As you begin cooling the solution, crystals
may slowly begin to form, or you may have to cool the crystallizing solution further (with ice) to
induce crystallization. In some cases, you have to physically disturb to cooled mixture to get
crystals to form. In any case, these are filtered, and you may see some color left in the filtrate,
this indicates that some impurities have remained in solution. The pure crystals should be white.
