If pressure acting on a liquid is decreased, the boiling point will

If pressure acting on a liquid is decreased, the boiling point will

• A. Boiling point decreases the temperature at which it will boil
• B. Boiling point increases the temperature at which it will boil
• C. No change
• D. The liquid freezes

Answer: (A)

Boiling occurs when a liquid’s vapor pressure equals the pressure pushing on it. If the surrounding pressure is lowered, the liquid only needs to reach a lower temperature for its vapor pressure to match that reduced pressure, so boiling starts at a lower temperature. This is why water boils at lower temperatures at high altitudes. The other options don’t fit because decreasing external pressure does not raise the boiling temperature, nor is there no change—the boiling point depends on the ambient pressure. Freezing isn’t the expected outcome from simply lowering pressure in this context.

Boiling occurs when a liquid’s vapor pressure equals the pressure pushing on it. If the surrounding pressure is lowered, the liquid only needs to reach a lower temperature for its vapor pressure to match that reduced pressure, so boiling starts at a lower temperature. This is why water boils at lower temperatures at high altitudes.

The other options don’t fit because decreasing external pressure does not raise the boiling temperature, nor is there no change—the boiling point depends on the ambient pressure. Freezing isn’t the expected outcome from simply lowering pressure in this context.