44 The melting point of seawater is -2 °C and the condensation point is 100.7 °C. What care its freezing Point and boiling point ?
The Correct Answer and Explanation is:
The freezing point of seawater is slightly lower than the freezing point of pure water due to the presence of dissolved salts. When salt is added to water, it lowers the freezing point in a phenomenon known as freezing point depression. For seawater, which typically has a salinity of around 3.5%, the freezing point is about -2°C, as you mentioned. This is because the salt ions disrupt the formation of the solid crystal structure of ice, requiring a lower temperature for the water to freeze.
The boiling point of seawater, however, is a bit higher than pure water, thanks to the dissolved salts. The boiling point elevation occurs because the presence of solutes like salt reduces the vapor pressure of the liquid, requiring a higher temperature to reach the boiling point. The boiling point of seawater is approximately 100.7°C, as given, which is slightly higher than the boiling point of pure water (100°C).
Freezing Point of Seawater
The freezing point of seawater is around -2°C. This value can vary slightly depending on the salinity of the seawater, with higher salinity causing a greater depression of the freezing point. In general, the more salt in seawater, the lower the freezing point.
Boiling Point of Seawater
The boiling point of seawater is around 100.7°C. The salt in seawater causes the boiling point to rise slightly above that of pure water due to the elevation of the boiling point with increasing solute concentration.
In summary:
- Freezing point of seawater: Around -2°C
- Boiling point of seawater: Around 100.7°C
These changes are caused by the effects of dissolved salts in seawater, which alter the physical properties of the water compared to pure water.
