[iamstupid]

it is given y*=mx (where m = 0.75 bar.m^3/kmol )

it is to calculate the y* with a given x mole fraction

should the m have unit or should dimensionless, if it is dimensionless, what should i do ? how should i get rid of (m^3/kmol)

[mbeychok]

Henry's law constants are reported in the technical literature in many, many different dimensional units and that can be very confusing. To learn more, read this article in the Citizendium online encyclopedia: click here ==> Henry's law

By the way, I think you meant gas absorption rather than adsorption.