How does pressure affect the boiling point of water?

The correct understanding of how pressure affects the boiling point of water is that the boiling point increases with increased pressure. This phenomenon is rooted in the principles of phase changes and the relationship between pressure and temperature.

When water boils, it transitions from a liquid state to a gas (steam). This process occurs when the vapor pressure of the liquid equals the surrounding atmospheric pressure. At higher pressures, more energy (in the form of heat) is required for the vapor pressure to reach that elevated surrounding pressure, resulting in a higher boiling point.

For example, in a pressure cooker, the increased pressure allows water to boil at temperatures above 100°C (212°F), which leads to faster cooking times. This principle is crucial in various industrial applications and equipment, such as boilers and autoclaves, where managing pressure can optimize processes.

In contrast, if the surrounding pressure is lower (such as at high altitudes), the boiling point decreases, which is why water boils at temperatures lower than 100°C in those conditions. The option that states the boiling point increases with increased pressure accurately illustrates this essential concept in thermodynamics and phase behavior of substances.