Mystery Hose (help identifying)

While inspecting the engine bay I came across a mysterious hose that’s seemingly and inexplicably disconnected. I don’t have a lot of experience working on cars to be able to identify what this hose is or its purpose, but I know enough to understand that something like this isn’t designed to just hang around loose on one end. Recently my Juke SL AWD has been driving strangely with a remarkable decrease in power. It feels like I’m driving a car with 3 cylinders instead of 4. I can feel a difference in how it drives, not to mention the new sounds that I’m hearing as it struggles to climb a hill or accelerate at a green light. Can anyone help me identify what this hose is and whether or not it’s supposed to be connected to something? Any insight or advice would be deeply appreciated. Thanks!