Using "Round Up" on a lawn

[Bienes Raices]

I've gotten some good suggestions on here for the lawn. I was originally going to leave it alone, but it's gotten really bad. There is so much clover and broad-leaf weeds in the backyard now that you can't see the underlying lawn anymore. I need to do some kind of one time treatment before the tenants move in a month from now, then it's their responsibility from then on.

Has anyone had success using Round Up or another similar product. Any recommendations (obviously I want to avoid killing the grass along with the weeds).