Calculate the volume of ovygen at STP collected at 25.0 L at 775 mm and 296 Kelvins. Yhe mercury level inside the tube is 28.0 mm higher than outside.

Please help me solve, I am at a loss :(

I'm sorry I can't help. It would help if you could draw a diagram of the set up but this board won't accommodate that. I don't know your set up.