The freezing point of glycerol is 17.8 °C, and its boiling point is 290 °C. Find its melting point and condensation point.
The correct answer and explanation is:
Correct Answer:
- Melting Point: 17.8 °C
- Condensation Point: 290 °C
Explanation:
The melting point of a substance is the temperature at which it changes from a solid to a liquid. The freezing point is the temperature at which it changes from a liquid to a solid. For pure substances like glycerol, the melting point and the freezing point are the same temperature. Therefore, since the freezing point of glycerol is given as 17.8 °C, its melting point is also 17.8 °C.
The condensation point is the temperature at which a substance changes from a gas to a liquid. It is the reverse of boiling. The boiling point is the temperature at which a liquid turns into vapor under standard atmospheric pressure. Since the process of condensation is simply the reverse of boiling, the condensation point occurs at the same temperature as the boiling point for a pure substance. Therefore, glycerol’s condensation point is 290 °C, the same as its boiling point.
The values for melting and condensation points are significant in understanding the physical behavior of substances. For glycerol, knowing these points helps in determining the temperature ranges suitable for its storage and usage. Glycerol remains in liquid form between 17.8 °C and 290 °C under normal atmospheric conditions. Outside this range, it exists either as a solid below 17.8 °C or as a gas above 290 °C.
These phase change temperatures are also critical in chemical manufacturing and laboratory work. During heating or cooling, temperature remains constant at these points until the phase transition is complete. This behavior is due to the energy being used to break or form intermolecular forces rather than changing temperature. In summary, glycerol’s melting point is 17.8 °C, and its condensation point is 290 °C, corresponding directly to its freezing and boiling points.