##  [Vapor–Liquid Equilibrium Ratio](/vapor-liquid-equilibrium-ratio) 

  ##  [Vapor–Liquid Equilibrium Ratio](https://engineering.quantumdictionary.io/vapor-liquid-equilibrium-ratio-0) 

  

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**Engineering & Applied Technologies Dictionary**

 







 

 

 

 



 

 

 

 

Definition

The equilibrium ratio Ki (K‑value) for component i defined as Ki = yi/xi, the ratio of the component mole fraction in the vapor phase (yi) to its mole fraction in the liquid phase (xi) at vapor–liquid thermodynamic equilibrium under specified temperature and pressure conditions; Ki is unitless and is a function of composition, temperature and pressure (and nonideality).