When i have my phone on mute for some reason it plays alarm EVEN when the phone is on mute which is annoying in library and often get comments about switching to iphone because of this.
Personally I want alarms to ring anytime that they are set.
If you want to prevent it while the phone is muted, try this:
If you go into sound settings when you're in your alarm app, there is an option to set the alarms to vibrate. So they will vibrate and not ring. I hope this helps! Thanks