alternating is fine. I tend to do circuits from time to time and thats alternating so your fine with that.
However I would changed from chest & back to chest and tris, back and bi’s as mentioned above. You want to group like muscle groups together, ones that emphasize the same ones because then your working the muscles at the same time, giving them time to rest in between days.
If you constantly are exercising them you aren’t giving them time to recover/heal/grow so that is why its better to group those together with each other. (also pretty much everything badazzss said haha)