$30.$ The Freundlich isotherm can be represented by the equation $\backslash ($ q $=$ K$\_$f $\backslash$cdot C$^\{1/$n$\}\backslash ),$ where $\backslash ($ K$\_$f $\backslash )$ and $\backslash ($ n $\backslash )$ are $\_\_\_\_\_\_\_\_\_\_.$