I read in a book that the boiling point of a certain substance is 50°C (at 0.5 mm Hg). What does that mean??
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As the title suggests, I read in a book that the boiling point of a certain substance is 50°C at 0.5 mm Hg. What does this mean? Generally, this value indicates the boiling point of a substance under standard pressure (760 mm Hg). Can this substance be purified by distillation? Is vacuum distillation a viable method?
It’s best to do a small-scale test in the lab now
As I understand it: Absolute pressure = gauge pressure + atmospheric pressure. If the boiling point is 50°C at an absolute pressure of 0.5 mmHg, then using the formula above, the gauge pressure would be 0.5 mmHg – 760 mmHg = -755 mmHg (torr). In other words, a very low vacuum level must be achieved in order to carry out purification distillation
The purification of a substance (distillation) depends not only on its boiling point but also on the difference in boiling points between it and impurities. The smaller the boiling point difference, the more difficult it is to separate and purify by distillation.
It’s really amazing to look at these characters that can’t be written. This kind of thing will break down at normal pressure, right?