Volume referred mass transfer coefficients k(L)a were determined for the slurries of 6 solids in water and n-butanol in a mechanically agitated reactor of standard configuration. The measurements were carried out under variation of power input, gas flow rate, and solids concentration. It is observed that inert solid particles used increased by a drastically compared to the case with pure water only. On the other hand, the same inert solid particles with the same solid volume, exhibited conflicting behaviour in suspensions of n-butanol.