Final answer:
At 50°C, benzene with a vapor pressure of 42.5 kPa is in the liquid phase, but the phase of isobutene at that temperature needs additional data to determine.
Explanation:
Vapor Pressure and Phase Change of Benzene:
- At 50°C:
- Benzene: At 50°C, with a vapor pressure of 42.5 kPa, benzene is in the liquid phase.
- Isobutene: Isobutene's phase at 50°C is dependent on its vapor pressure, not directly provided in the information.
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