  We derive some geometric properties of chordal SLE$(\kappa;\vec{\rho})$
processes. Using these results and the method of coupling two SLE processes, we
prove that the outer boundary of the final hull of a chordal
SLE$(\kappa;\vec{\rho})$ process has the same distribution as the image of a
chordal SLE$(\kappa';\vec{\rho'})$ trace, where $\kappa>4$,
$\kappa'=16/\kappa$, and the forces $\vec{\rho}$ and $\vec{\rho'}$ are suitably
chosen. We find that for $\kappa\ge 8$, the boundary of a standard chordal
SLE$(\kappa)$ hull stopped on swallowing a fixed $x\in\R\sem\{0\}$ is the image
of some SLE$(16/\kappa;\vec{\rho})$ trace started from $x$. Then we obtain a
new proof of the fact that chordal SLE$(\kappa)$ trace is not reversible for
$\kappa>8$. We also prove that the reversal of SLE$(4;\vec{\rho})$ trace has
the same distribution as the time-change of some SLE$(4;\vec{\rho'})$ trace for
certain values of $\vec{\rho}$ and $\vec{\rho'}$.
