I don't even want to imagine what Murphy's roommate could possibly have done to elicit this kind of payback...
Again in my freshman year at Rutgers, more fun with chemistry. My roommate Larry was taking a chemistry class and learned about acids. He was scared to death of touching any. We told him that it was inevitable that he could eventually touch some in chem lab, which he hated.
So we decided to have some (more) fun with him, at his expense of course! I got some concentrated sulphuric acid from my chem lab class and brought it back to the dorm. We liberally sprinkled it on some of his dirty blue jeans, and waited for holes to appear. Much to our chagrin, nothing happened…………….. nothing at all! We were confused and disappointed to be sure.
However, we got our jollies a few days later when Larry finally washed his jeans. They came out of the dryer festooned with what looked like bullet holes from the waist to the cuffs, literally hundreds of holes. Larry showed us in puzzlement, and as soon as any of us were able to recover our breath from laughing, we told him and he must had gotten a lot of acid exposure, and he should stand in a shower immediately for at least an hour. Sadly we told him, only COLD water would be effective in purging his system of the deadly chemical. I don't know which was the most fun, seeing his swiss-cheese pants or watching him shiver in a shower for an hour!
For those of you who wonder, yes, I did go to classes, and yes I did graduate, and no, I don't torture small animals for fun.
I've spilt battery acid (which is sulfuric acid, and fairly concentrated) on my clothes a few times and although my clothes had permanent scars, I didn't. Once it's dried it's pretty harmless, and the fabric holds its structure until you wash it. It's certainly not something you'd want to get in your eyes, though.
I would agree with Himanshu_Gupta, that sulfuric acid, concentrated or diluted, is certainly not anything to play around with. If your room mate had decided to wear those dirty jeans another day he would have had some nasty acid damage and sulfuric ion poisoning. Probably not fatal, but very uncomfortable and with permanent scars. Some attempts at pranks are a very poor choice.