Weird gas

No.10882978 ViewReplyOriginalReport
So I was mixing random stuff and I mixed sr(no3)2, nahso4, cuso4 and then poured it into a little dish with magnesium and it immediately fizzled up and let off a weird white gas that looked like water vapor. I thought it was hydrogen, but it smelled like so2 and bleach. Any clue what it might've been?