Statement-1:  $SbC{l}_5$ is more covalent than  $SbC{l}_3$   
Statement-2 : The higher oxides of halogens are tend to be more stable than the lower ones.  

According to Fajan’s rule $S{b}^{+5}$ has more polarizing power than $S{b}^{+3}.$ Therefore $SbC{l}_5$ is more covalent than $SbC{l}_3$. 
Stability of higher oxides of halogen is primarily due to Higher oxidation state  
More electronegative halogen
Resonance stabilization