The reason is not 'lsb' ( redhat-lsb ) or 'xdg-utils'.
The are easy to install with # yum install redhat-lsb xdg-utils
But down the road you will meet a missing libstdc++.so.6.
The version, you have is too old, and cannot be replaced.
EL5 is too old for that package, as said by @ DrLove73
You can use the EL5 / CentOS54 google-chrome package
cd chrome/ && ./chrome-wrapper
... will display the google chrome browser.