def molar_flux_HNS(k, area, sol, wat_conc,x = 1):
    """
    Return the dissolution molar flux [mol/s]
    source : (HNS-MS)

    Parameters
    ----------
    k : Mass transfert coefficient [m/s]
    area : Area of the slick [m²]
    sol : Pure component solubility [mol/m³]
    wat_conc : Water concentration of the component [mol/m³]
    x : molar fraction of the compounds, the default is 1


    """
    return k * area * (x * sol - wat_conc)