For Freundlich adsorption isotherm,
\[
\log\left(\frac{x}{m}\right)
=
\log k+\frac{1}{n}\log P
\]
Always remember:
\[
\text{Intercept}=\log k
\]
\[
\text{Slope}=\frac{1}{n}
\]
Hence, if the intercept is known, \(k\) can be obtained directly by taking antilog.