The Antoine equation is primarily used for what purpose?

The Antoine equation is a mathematical formula used to estimate the vapor pressures of pure liquids or solids as a function of temperature. It provides a relationship between the temperature and the vapor pressure of a substance, which is essential in various fields, including chemistry, chemical engineering, and environmental science.

This equation is particularly useful because it allows for the approximation of vapor pressures over a specified temperature range without requiring extensive experimental data. By using coefficients specific to each compound, the Antoine equation can yield accurate vapor pressure values needed for calculations in processes such as distillation, evaporation, and other scenarios involving phase changes.

The other options mentioned do not align with the primary application of the Antoine equation. Calculating altitude involves different equations and methods pertaining to atmospheric pressure and temperature, while fuel efficiency concerns are generally evaluated through different parameters related to combustion and thermodynamics.