The 5.25" drive is only useful for a Mac if you've got an LC with an Apple IIe card.
Another tip: if you got drives from systems with two drives, use the one marked drive 2. It likely hasn't been used much and will be less worn out.
3.5" drives, when next to 5.25" drives, are usually used less on academic environment IIGS machines simply because schools had a lot more software on the 5.25" disks. In fact, I've seen IIGS machines being used exclusively with 5.25" disks in schools.