At 0 psi, _______ BTUs are necessary to change 1 lb of water from a liquid at 212°F into steam.

To convert 1 pound of water at 212°F into steam at 0 psi, the required energy is known as the latent heat of vaporization. At standard atmospheric pressure, this value is typically about 970.3 BTUs. The latent heat of vaporization is the amount of heat required to change a substance from liquid to vapor without changing its temperature.

In practical terms, this means that when you have water at its boiling point (212°F), you need to add approximately 970.3 BTUs of energy to convert that water into steam. This process involves breaking the molecular bonds in the liquid water, allowing it to transition into steam, which requires a significant amount of energy despite the temperature remaining constant during the phase change.

This value of 970.3 BTUs is a critical concept in thermodynamics and steam engineering, as it helps engineers determine the energy requirements for steam production in various applications. Understanding the latent heat of vaporization is essential for efficient boiler operation and steam generation processes.