Consider interphase mass transfer of a species $S$ between two immiscible liquids $A$ and $B$. The interfacial mass transfer coefficient ot $S$ in liquid $A$ is twice of that in liquid $B$. The equilibrium distribution of $S$ between the liquids is given by $y_{S}^{A} = 0.5 \:y_{S}^{B}$, where $y_{S}^{A}$ and $y_{S}^{B}$ are the mole-fractions of $S$ in $A$ and $B$, respectively. The bulk phase mole-fraction of $S$ in $A$ and $B$ is $0.10$ and $0.02$, respectively. If the steady-state flux of $S$ is estimated to be $10\: \text{kmol}\:h^{-1}\:m^{-2}$, the mass transfer coefficient of $S$ in $A$ is ___________________ $\text{kmol}$ $h^{-1}\:m^{-2}$ (rounded off to one decimal place).