Explain why pure liquids and solids can ignored while writing the equilibrium constant expression?

Explanation

For the concentration of pure solid or pure liquid,
[Solid ] or [liquid]= `"No. of moles"/"Volume in L"`
`="Mass /Molar mass"/"Volume"`
`="Mass"/"Volume" xx 1/"Molar mass"`
`="Density"/"Molar mass"`
Since density of pure solids and liquids is constant at constant temperature and molar mass is also constant, therefore, their molar concentrations are constant and are not included in the equilibrium constant.