Stop and think

6. There are many variations on most purification techniques. One problem that could happen in a recrystallization is that there is a very insoluble impurity. How could this very insoluble impurity be separated from the rest of the sample? What precautions must be taken in doing so?

7. Suppose you are trying to recrystallize a sample of borneol. You think it should be recrystallized from methanol. You add a couple of mL of cold methanol and the sample all dissolves. Evaluate the prognosis of your recrystallization: is it working well? If not, what do you need to do?

8. Suppose you are trying to recrystallize a sample of borneol. You think it should be recrystallized from methanol. You add a couple of mL of cold methanol and only about half the sample dissolves. Evaluate the prognosis of your recrystallization: is it working well? If not, what do you need to do?

9. Suppose you are trying to recrystallize a sample of borneol. You think it should be recrystallized from methanol. You add a couple of mL of hot methanol and only about half the sample dissolves. Evaluate the prognosis of your recrystallization: is it working well? If not, what do you need to do?

Растворимость хлорида никеля в воде, г/100г:

53,4 (0°), 59,5 (10°), 65,6 (25°), 76 (50°), 86,2 (75°), 87,7 (100°)

Растворимость хлорида железа в воде, г/100г:

49,7 (0°), 62,6 (20°), 68,6 (40°), 78,3 (60°), 94,2 (100°)

Очень близкие значения