The temperature at which ice, water and vapor remain in equilibrium is called

The triple point is the specific temperature and pressure at which ice, liquid water, and water vapor can coexist in thermodynamic equilibrium. For water, this occurs at exactly 273.16 K (0.01°C) and a pressure of 611.657 pascals. The triple point is a fundamental concept in thermodynamics and is used to define the Kelvin temperature scale.

Among the given options:
– [A] Freezing point refers to the temperature at which a liquid turns into a solid.
– [B] Boiling point is the temperature at which a liquid turns into vapor.
– [C] Critical temperature is the temperature above which a gas cannot be liquefied, regardless of pressure.
– [D] Triple point is the correct term for the temperature and pressure where ice, water, and vapor are in equilibrium.

Thus, the correct answer is [D] Triple point.