* Phase Diagram: The relationship between pressure, temperature, and the different phases of matter (solid, liquid, gas) is represented by a phase diagram. For bromine, the solid phase is denser than the liquid phase.
* Le Chatelier's Principle: Le Chatelier's Principle states that a system at equilibrium will shift to relieve stress. In this case, increasing the external pressure puts a "stress" on the system. To relieve this stress, the system will shift towards the denser phase, which is the solid phase for bromine. This means more bromine will solidify, and the melting point will increase.
Key Points:
* Normal Melting Point: The melting point of bromine at standard atmospheric pressure (1 atm) is -7.2 °C (19.0 °F).
* Density Relationship: The solid phase of bromine is denser than the liquid phase, unlike water. This is crucial for understanding the pressure-melting point relationship.
Practical Example:
Imagine you have a container of liquid bromine. If you increase the pressure on the container, you'll force the bromine molecules closer together. This makes it harder for the molecules to move freely, increasing the energy needed to break the intermolecular bonds and transition to a liquid state. Consequently, the melting point increases.
Note: The effect of pressure on the melting point is generally much smaller than the effect of pressure on the boiling point.
