try: kdesudo -u test chromium

The problem with this which I realized now is I have created a new account and didnt login with that account. Chromium doesn't come by default. So if I type this it will say chromium unavailable rt?

when an app is installed using the package management facility (which dl's and installs a .deb(s) in the case of Kubuntu) it is installed under /usr and available for all users on the system